Lesson 14 - Activity 1

Transcription

1 13 Lesson 14 - Activity 1 / Term 1: Lesson 14 Coding Activity 1 Test if an integer is not between 5 and 76 inclusive. Sample Run 1 Enter a number: 7 False Sample Run 2 Enter a number: 1 True / class Lesson_14_Activity_One public static void main(string[] args) //Declare a scanner and input an int. System.out.println("Please enter an integer:"); int n = scan.nextint(); //If n is not in the range, print True. if (!( n >= 5 && n <= 76)) System.out.println("True"); //Otherwise, print False. else System.out.println("False"); APCS Unit 2 Activity Guide Version 1.0 Edhesive

2 14 Lesson 14 - Activity 2 / Term 1: Lesson 14 Coding Activity 2 Write a program to input two integers and print "Both are positive or zero." to the screen, if both are positive or zero. Print "One or both are negative." otherwise. / class Lesson_14_Activity_Two public static void main(string[] args) //Declare a Scanner and input two integers. System.out.println("Please enter two integers:"); int x = scan.nextint(); int y = scan.nextint(); //Use if-else to produce the necessary output. if(x >= 0 && y >= 0) System.out.println("Both are positive or zero."); else System.out.println("One or both are negative."); APCS Unit 2 Activity Guide Version 1.0 Edhesive

3 15 Lesson 14 - Activity 3 / Term 1: Lesson 14 Coding Activity 3 The Internet runs on web addresses.the addresses we type represent the IP address for each site and how the computer finds an individual web page. IP addresses are made up of four numbers, each between 0 and 255 separated by a period. For example, is an IP address. Write a program to enter four numbers and test if they make up a valid IP address. In other words, test to see if the numbers entered are between 0 and 255 inclusive. Sample Run 1 Please enter the first octet: 898 Please enter the second octet: 34 Please enter the third octet: 712 Please enter the fourth octet: 45 Octet 1 is incorrect Octet 3 is incorrect Sample Run 2 Please enter the first octet: 112 Please enter the second octet: 200 Please enter the third octet: 0 Please enter the fourth octet: 254 IP Address: / class Lesson_14_Activity_Three public static void main(string[] args) //Declare a Scanner and input four octets. APCS Unit 2 Activity Guide Version 1.0 Edhesive

4 16 System.out.println("Please enter the first octet: "); int o1 = scan.nextint(); System.out.println("Please enter the second octet: "); int o2 = scan.nextint(); System.out.println("Please enter the third octet: "); int o3 = scan.nextint(); System.out.println("Please enter the fourth octet: "); int o4 = scan.nextint(); //Set up a flag variable for correct input. int correct = 1; //Check octet 1. if (!(o1 >= 0 && o1 <= 255)) System.out.println("Octet 1 is incorrect"); correct = 0; //Check octet 2. if (!(o2 >= 0 && o2 <= 255)) System.out.println("Octet 2 is incorrect"); correct = 0; //Check octet 3. if (!(o3 >= 0 && o3 <= 255)) System.out.println("Octet 3 is incorrect"); correct = 0; // Check octet 4. if (!(o4 >= 0 && o4 <= 255)) System.out.println("Octet 4 is incorrect"); correct = 0; //Check the flag for a correct IP address. if (correct == 1) System.out.println("IP Address: " + o1 + "." + o2 + "." + o3 + "." + o4); APCS Unit 2 Activity Guide Version 1.0 Edhesive

5 17 Lesson 17 - Activity 1 / Term 1: Lesson 17 Coding Activity 1 Write a program that will input a list of test scores in from the keyboard. When the user enters -1, print the average. What do you need to be careful about when using -1 to stop a loop? Sample Run: Enter the Scores: The average is: 72.5 / import java.lang.math; class Lesson_17_Activity_One public static void main(string[] args) //Declare a Scanner and prompt for scores. System.out.println("Enter the Scores: "); //Input the first score and declare sum and count variables. int test = scan.nextint(); int sum = 0; int c = 0; //While the input is not -1, increase the count, //add to the sum, and read the next input. while (test!= -1) sum += test; c++; test = scan.nextint(); //Calculate and print the average. System.out.println("The average is: " + 1.0sum/c); APCS Unit 2 Activity Guide Version 1.0 Edhesive

6 18 Lesson 17 - Activity 2 / Term 1: Lesson 17 Coding Activity 2 Ask the user for two numbers. Print only the even numbers between them, you should also print the two numbers if they are even. Sample Run 1: Enter two numbers: Sample Run 2: Enter two numbers: / import java.lang.math; class Lesson_17_Activity_Two public static void main(string[] args) //Declare a Scanner and input two numbers. System.out.println("Enter two numbers: "); int a = scan.nextint(); int b = scan.nextint(); //Create a new variable, start, which is a rounded //up to the nearest even number. int start = a + (a%2); //While start is in range, print it and increase by 2. while (start <= b) System.out.print(start + " "); start += 2; APCS Unit 2 Activity Guide Version 1.0 Edhesive

7 19 Lesson 20 - Activity 1 / Term 1: Lesson 20 Coding Activity Computer science jobs are in demand. Right now we have a shortage of people that can do computer programming, and one of the fastest growing areas of new jobs in the sector are so-called hybrid jobs. This means you specialize in an area like biology, and then use computer programming to do your job. These hybrid jobs exist in the arts, sciences, economics, healthcare, and entertainment fields. One of these jobs is computational biology. Computational Biology, sometimes referred to as bioinformatics, is the science of using biological data to develop algorithms and relations among various biological systems. In this lab we are going to investigate the data from a grey seal named Gracie. We ll input the longitude and latitude data from a tracking device. We want to investigate the farthest north, south, east and west Gracie has been. We will use the latitude to measure this. Write a program to enter Gracie s longitude and Latitude data. Each time through the loop it should ask if you want to continue. Enter 1 to repeat, 0 to stop. Any value for latitude not between -90 and 90 inclusive should be ignored. Any value for longitude not between -180 and 180 inclusive should be ignored. Sample Run: Please enter the latitude: Please enter the longitude: Would you like to enter another location? 1 Please enter the latitude: Please enter the longitude: Would you like to enter another location? 1 Please enter the latitude: Please enter the longitude: APCS Unit 2 Activity Guide Version 1.0 Edhesive

8 20 Would you like to enter another location? 1 Please enter the latitude: 300 Please enter the longitude: Incorrect Latitude or Longitude Please enter the latitude: Please enter the longitude: Would you like to enter another location? 0 Farthest North: Farthest South: Farthest East: Farthest West: / import java.lang.math; class Lesson_20_Activity public static void main(string[] args) //Declare a Scanner. //Set a flag variable, rep, to control the loop. int rep = 1; //Set up temporary variables to store the current location. double lo = 0; double la = 0; //Set up a max and min for latitude and longitude. double maxlat = -90; double minlat = 90; double maxlon = -180; double minlon = 180; APCS Unit 2 Activity Guide Version 1.0 Edhesive

9 21 //While rep == 1, continue the loop. while (rep == 1) //Input a lat and long value. System.out.println("Please enter the latitude: "); la = scan.nextdouble(); System.out.println("Please enter the longitude: "); lo = scan.nextdouble(); //If the values are invalid, print an error, //and continue the loop. if (!(la >= -90 && la <= 90)!(lo >= -180 && lo <= 180)) System.out.println( "Incorrect Latitude or Longitude"); //Otherwise, check for a new max or min and ask the //user if they would like to continue. else if(la > maxlat) maxlat = la; if(la < minlat) minlat = la; if(lo > maxlon) maxlon = lo; if(lo < minlon) minlon = lo; //while System.out.println( "Would you like to enter another location? "); rep = scan.nextint(); //Print the results. System.out.println("Farthest North: " + maxlat); System.out.println("Farthest South: " + minlat); System.out.println("Farthest East: " + maxlon); System.out.println("Farthest West: " + minlon); APCS Unit 2 Activity Guide Version 1.0 Edhesive

10 1 Lesson 22 - Activity 1 / Term 1: Lesson 22 Coding Activity 1 Write the code to take a String and print it with one letter per line. Sample run: Enter a string: bought b o u g h t / import java.lang.math; class Lesson_22_Activity_One public static void main(string[] args) //Declare a Scanner and input a String. System.out.println("Enter a string:"); String h = scan.nextline(); //Loop through the String, printing each character. int i = 0; while (i < h.length()) System.out.println(h.charAt(i)); i++; APCS Unit 3 Activity Guide Version 1.0 Edhesive

11 2 Lesson 22 - Activity 2 / Term 1: Lesson 22 Coding Activity 2 Write the code to take a String and print it diagonally. Sample run: Enter a string: bought b o u g h t Use a tab character for every four spaces in the sample. Hint: You may need more than one loop. / import java.lang.math; class Lesson_22_Activity_Two public static void main(string[] args) //Declare a Scanner and input a String. System.out.println("Enter a string:"); String h = scan.nextline(); //For each character, use a loop to print tabs //so that the ith character is preceded by //i tabs. int i = 0; while (i < h.length()) int j = 0; while(j < i) System.out.print("\t"); j++; System.out.println(h.charAt(i)); i++; APCS Unit 3 Activity Guide Version 1.0 Edhesive

12 3 Lesson 24 - Activity 1 / Term 1: Lesson 24 Coding Activity 1 Use a for loop to print all of the numbers from 23 to 89, with 10 numbers on each line. Print one space between each number. / import java.lang.math; class Lesson_24_Activity_One public static void main(string[] args) //Loop from 23 to 89. for (int i = 23; i <= 89; i++) //Print each number followed by a space. System.out.print(i + " "); //Use % to print a new line every 10 numbers. if( i % 10 == 2) System.out.println(); Lesson 24 - Activity 2 / Term 1: Lesson 24 Coding Activity 2 Use a for loop to print the even numbers between 1 and 50. Print each number on a new line. / import java.lang.math; class Lesson_24_Activity_Two public static void main(string[] args) //Loop through the numbers from 1 to 50. for (int i = 1; i <= 50; i++) //If a number is even, print it. if (i%2 == 0) System.out.println(i); APCS Unit 3 Activity Guide Version 1.0 Edhesive

13 4 Lesson 24 - Activity 3 / Term 1: Lesson 24 Coding Activity 3 Input an int between 0 and 100 and print the numbers between it and 100. If the number is not between 0 and 100 print "error". Print 20 numbers per line. Sample Run 1: Enter a number between 0 and 100: Sample Run 2: Enter a number between 0 and 100: 105 error / import java.lang.math; class Lesson_24_Activity_Three public static void main(string[] args) //Declare a Scanner and input a number. System.out.println("Enter a number between 0 and 100"); int x = scan.nextint(); //If x is out of range, print error. if( x < 0 x > 100) System.out.println("error"); //Otherwise, use a for loop to print every number from x to 100. //Use modular division to print 20 numbers per line. else for(int i = x; i <= 100; i++) System.out.print(i + " "); if(i%20 == 0) System.out.println(); APCS Unit 3 Activity Guide Version 1.0 Edhesive

14 5 Lesson 29 - Activity 1 / Term 1: Lesson 29 Coding Activity 1 A student wants an algorithm to find the hardest spelling word in a list of vocabulary. They define hardest by the longest word. Write the code to find the longest word stored in an array of Strings called list. If several words have the same length it should print the first word in list with the longest length. For example, if the following list were declared: String list [] = "high", "every", "nearing", "checking", "food ", "stand", "value", "best", "energy", "add", "grand", "notation", "abducted", "food ", "stand"; It would print: checking / import java.lang.math; class Lesson_29_Activity_One / Fill this list with values that will be useful for you to test. A good idea may be to copy/paste the list in the example above. Do not make any changes to this list in your main method. You can print values from list, but do not add or remove values to this variable. / public static String [] list = "This","is","a","test","list"; public static void main(string[] args) //Declare a variable to store the location of the longest String. int longest = 0; //Loop through the list, searching for a String longer than //longest. for(int i = 0; i < list.length; i++) if(list[i].length() > list[longest].length()) longest = i; //Print the longest value in the list. System.out.println(list[longest]); APCS Unit 3 Activity Guide Version 1.0 Edhesive

15 6 Lesson 29 - Activity 2 / Term 1: Lesson 29 Coding Activity 2 Write a loop that processes an array of strings. Each String should be printed backwards on its own line. For example, if the list contains: "every", "nearing", "checking", "food", "stand", "value" It should output: yreve gniraen gnikcehc doof dnats eulav / import java.lang.math; class Lesson_29_Activity_Two / Fill this list with values that will be useful for you to test. A good idea may be to copy/paste the list in the example above. Do not make any changes to this list in your main method. You can print values from list, but do not add or remove values to this variable. / public static String [] list = "siht","si","a","tset","tsil"; public static void main(string[] args) //Use a for loop to access each String in the list. for(int i = 0; i < list.length; i++) //Loop through each String backwards, printing the //characters. for(int j = list[i].length() - 1; j >= 0; j--) System.out.print(list[i].charAt(j)); //print a new line after each String. System.out.println(); APCS Unit 3 Activity Guide Version 1.0 Edhesive

16 7 Lesson 30 - Activity 1 / Term 1: Lesson 30 Coding Activity Due to a problem with a scanner an array of words was created with spaces in incorrect places. Write the code to process the list of words and trim any spaces out of the words. So if the list contains: "every", " near ing ", " checking", "food ", "stand", "value " It should be changed to hold: "every", "nearing", "checking", "food", "stand", "value" Note that this activity does not require you to print anything. Your code should end with the array list still declared and containing the resulting words. / class Lesson_30_Activity / Your code should end with the following array modified as the instructions above specify. You may modify the elements in this list but make sure you do not add or remove anything from it. / public static String [] list = "Th is"," is","a ","t es t","li st"; public static void main(string[] args) //Loop through the list to access each String. for(int i = 0; i < list.length; i++) //Declare a new String to include only the non-space //characters. String tmp = ""; //For each character in the current String, if it is not //a space, add it to the temporary String, tmp. for(int j = 0; j < list[i].length(); j++) if( list[i].charat(j)!= ' ') tmp += list[i].charat(j); //Set the current String to the value of tmp. list[i] = tmp; APCS Unit 3 Activity Guide Version 1.0 Edhesive

17 8 Lesson Activity 1 / Term 1: Lesson 1011 Coding Activity Input a String to represent the octal number and translate to the base ten number. The octal number must be 8 digits or less. Your program should also check that all the digits are 0-7, then translate the number to base ten. Sample Run 1: Enter a number in base 8: 1287 ERROR: Incorrect Octal Format Sample Run 2: Enter a number in base 8: Sample Run 3: Enter a number in base 8: ERROR: Incorrect Octal Format / import java.lang.math; class Lesson_1011_Activity public static void main (String str[]) //Set up a Scanner and input a base 8 number as a String. Scanner scan = new Scanner (System.in); System.out.println("Enter a number in base 8: "); String oct1 = scan.nextline(); //Use a loop to check for valid input. for (int i = 0; i < oct1.length(); ++i) //Check for invalid ith character. if(i >= 8!(oct1.charAt(i) >= '0' && oct1.charat(i) <= '7')) //Print an error and return. System.out.println("ERROR: Incorrect Octal Format"); return; APCS Unit 3 Activity Guide Version 1.0 Edhesive

18 9 //Declare an int to store the value of our base 8 number. int a = 0; //Get the highest power of 8 int highestpower = oct1.length()-1; //use a loop to sum the value of each digit, multiplied //by 8 to the power of that digit. for (int i = 0; i < oct1.length(); ++i) a += ((oct1.charat(i)) - 48) Math.pow(8, highestpower-i); //Print the result. System.out.println(a); APCS Unit 3 Activity Guide Version 1.0 Edhesive

19 1 Lesson 32 - Activity 1 / Term 1: Lesson 32 Coding Activity 1 For the Lesson 32 activities, you will be asked to write one or more methods. Use the template to write a main method that tests each of your methods, then paste everything into the code runner box. Your submission should begin with the first import statement and end with the final. Write a method that takes a parameter for the number of a month and prints the month's name. This method must be called monthname() and it must have an integer parameter. Calling monthname(8) should print August to the screen. / import java.io.; class Lesson_32_Activity_One public static void monthname(int m) //Use if statements to check for each month individually. //Alternatively, students may create a String array and use //the variable m to access the month, as in the //following commented out code. / String [] months = "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"; return months[m - 1]; / if (m == 1) System.out.println("January"); if (m == 2) System.out.println("February"); if (m == 3) System.out.println("March"); if (m ==4) System.out.println("April"); if (m == 5) System.out.println("May"); if (m == 6) System.out.println("June"); if (m == 7) System.out.println("July"); if (m == 8) System.out.println("August"); if (m == 9) System.out.println("September"); if (m == 10) System.out.println("October");

20 2 if (m == 11) System.out.println("November"); if (m == 12) System.out.println("December"); //main method to test the program. This is not required by the //code runner, but is an important step in writing new methods. public static void main(string [] args) System.out.println("Enter a month number:"); int m = scan.nextint(); System.out.println("monthName(" + m + ") prints:"); monthname(m);

21 3 Lesson 32 - Activity 2 / Term 1: Lesson 32 Coding Activity 2 For the Lesson 32 activities, you will be asked to write one or more methods. Use the template to write a main method that tests each of your methods, then paste everything into the code runner box. Your submission should begin with the first import statement and end with the final. Write a method that takes a parameter for the number of a month and prints the number of days in the month. Assume that February will always have 28 days for this activity. This method must be called monthdays()and it must take an integer parameter. Calling monthdays(2) would print 28 and monthdays(9) would print 30. / import java.io.; class Lesson_32_Activity_Two public static void monthdays(int m) //There are three possible values for monthdays: 28, 30, or 31. //A three part if-else construction is used to return the appropriate //value. if (m == 4 m == 6 m == 9 m == 11) System.out.println(30); else if (m == 2 ) System.out.println(28); else System.out.println(31); //main method to test the program. This is not required by the //code runner, but is an important step in writing new methods. public static void main(string [] args) System.out.println("Enter a month number:"); int m = scan.nextint(); System.out.println("monthDays(" + m + ") prints:"); monthdays(m);

22 4 Lesson 32 - Activity 3 / Term 1: Lesson 32 Coding Activity 3 For the Lesson 32 activities, you will be asked to write one or more methods. Use the template to write a main method that tests each of your methods, then paste everything into the code runner box. Your submission should begin with the first import statement and end with the final. Write a method that takes two integer parameters and prints them in reverse. This method must be called swap and should take two integer parameters. Calling swap(3, 7) would print 7 3. / import java.io.; class Lesson_32_Activity_Three public static void swap (int a, int b) //Print a and b in reverse order System.out.println(b + " " + a); //main method to test the program. This is not required by the //code runner, but is an important step in writing new methods. public static void main(string [] args) System.out.println("Enter two numbers:"); int a = scan.nextint(); int b = scan.nextint(); System.out.println("Swap(" + a + ", " + b + ") prints:"); swap(a,b);

23 5 Lesson 32 - Activity 4 / Term 1: Lesson 32 Coding Activity 4 For the Lesson 32 activities, you will be asked to write one or more methods. Use the template to write a main method that tests each of your methods, then paste everything into the code runner box. Your submission should begin with the first import statement and end with the final. Write a method that accepts a number of seconds and prints the correct number of hours, minutes and seconds. This method must be called realtime() and its parameter must be an integer. Calling realtime(6342) would print the following: Hours: 1 Minutes: 45 Seconds: 42 / import java.io.; class Lesson_32_Activity_Four public static void realtime (int s) //There are 3600 seconds in an hour. Divide to determine the //number of hours. System.out.println("Hours: " + s / (3600) ); //Use modular division to recover the remaining seconds and //divide by 60 to convert to minutes. s = s % (3600); System.out.println("Minutes: " + s / 60); //Again, use mod to recover the remaining seconds. //Recall that s %= 60 is equivalent to s = s % 60 s %= 60; System.out.println("Seconds: " + s); //main method to test the program. This is not required by the //code runner, but is an important step in writing new methods. public static void main(string [] args) System.out.println("Enter a number of seconds:"); int s = scan.nextint(); System.out.println("realTime(" + s + ") prints:"); realtime(s);

24 6 Lesson 33 - Activity 1 / Term 1: Lesson 33 Coding Activity 1 For the Lesson 33 activities, you will be asked to write one or more methods. Use the template to write a main method that tests each of your methods, then paste everything into the code runner box. Your submission should begin with the first import statement and end with the final. For questions 2-5, you may want to start with the printit method and use it to test the other three. Write a method that takes an array of Strings and changes of the Strings to UPPER CASE. This method must be called upper() and it must take a String[] parameter. Use T1_L33_Reference_Tempate.java, which is included in this folder, as a reference. / import java.io.; class Lesson_33_Activity_One public static void upper(string [] a) //Use a for loop to process each index in an array for(int i = 0; i < a.length; i++) //At each i, change the ith string to uppercase by storing //the results of a[i].touppercase() in a[i]. a[i] = a[i].touppercase(); //main method to test the program. This is not required by the //code runner, but is an important step in writing new methods. public static void main(string [] args) System.out.println("Enter a positive number" + " indicating the length of an array:"); int n = scan.nextint(); String [] a = new String [n]; for(int i = 0; i < n; i++) System.out.println("Enter a String:"); a[i] = scan.next(); System.out.println("Calling upper() on the values you entered" + " changes the array to the following:"); upper(a); for(int i = 0; i < a.length; i++) System.out.println(a[i]);

25 7 Lesson 33 - Activity 2 / Term 1: Lesson 33 Coding Activity 2 For the Lesson 33 activities, you will be asked to write one or more methods. Use the template to write a main method that tests each of your methods, then paste everything into the code runner box. Your submission should begin with the first import statement and end with the final. For questions 2-5, you may want to start with the printit method and use it to test the other three. Write a method that takes an array of ints and stores random numbers between 10 and 99 in the array. Use Math.random() to generate random numbers and convert them to integers between 10 and 99 inclusive. This method must be called randomize() and it must take an int[] parameter. / import java.io.; class Lesson_33_Activity_Two public static void randomize(int [] a) //This is similar to problem 1, but we are storing the result of //Math.random() in an in array instead of processing Strings. for (int i = 0; i < a.length; i++) a[i] = (int) (Math.random()90) + 10; //main method to test the program. This is not required by the //code runner, but is an important step in writing new methods. public static void main(string [] args) System.out.println("Enter a positive number" + " indicating the length of an array:"); int n = scan.nextint(); int [] a = new int [n]; randomize(a); System.out.println("First call to randomize:"); for(int i = 0; i < a.length; ++i) System.out.println(a[i]); randomize(a); System.out.println("Second call to randomize:"); for(int i = 0; i < a.length; ++i) System.out.println(a[i]);

26 8 Lesson 33 - Activity 3 / Term 1: Lesson 33 Coding Activity 3 For the Lesson 33 activities, you will be asked to write one or more methods. Use the template to write a main method that tests each of your methods, then paste everything into the code runner box. Your submission should begin with the first import statement and end with the final. For questions 2-5, you may want to start with the printit method and use it to test the other three. Write a method that takes an array of ints and prints the array on a single line. Print one space between each number. This method must be called printit() and it must take an int[] parameter. / import java.io.; class Lesson_33_Activity_Three public static void printit(int [] a) for (int i = 0; i < a.length; i++) //Print the ith element of a followed by a single space, //using System.out.print so that all output is printed //on a single line. System.out.print(a[i] + " "); //Print a newline after running the loop System.out.println(); //main method to test the program. This is not required by the //code runner, but is an important step in writing new methods. public static void main(string [] args) System.out.println("Enter a postivite number" + " indicating the length of an array:"); int n = scan.nextint(); int [] a = new int [n]; for(int i = 0; i < n; ++i) System.out.println("Enter any integer:"); a[i] = scan.nextint(); System.out.println("Using printit to print an array of" + " those numbers prints the following:"); printit(a);

27 9 Lesson 33 - Activity 4 / Term 1: Lesson 33 Coding Activity 4 For the Lesson 33 activities, you will be asked to write one or more methods. Use the template to write a main method that tests each of your methods, then paste everything into the code runner box. Your submission should begin with the first import statement and end with the final. For questions 2-5, you may want to start with the printit method and use it to test the other three. Write a method that takes an array of ints and reverses the order of the values in the array. So the array 1, 2, 3 would be changed to 3, 2, 1 This method must be called reverse() and it must take an int[] parameter. / import java.io.; class Lesson_33_Activity_Four public static void reverse (int a[]) //Create a temporary array to store the values of a int temp[] = new int[a.length]; //Use a for loop to copy a into temp for (int i = 0; i < a.length; i++) temp[i] = a[i]; //Use a second for loop to copy temp back into a, //but using length-1-i to access the values of //temp in reverse order. for (int i = 0; i < a.length; i++) a[i] = temp[a.length i]; //main method to test the program. This is not required by the //code runner, but is an important step in writing new methods. public static void main(string [] args) System.out.println("Enter a postivite number" + " indicating the length of an array:"); int n = scan.nextint(); int [] a = new int [n];

28 10 for(int i = 0; i < n; ++i) System.out.println("Enter any integer:"); a[i] = scan.nextint(); System.out.println("Before calling reverse(a):"); printit(a); reverse(a); System.out.println("After calling reverse(a):"); printit(a); //include printit for testing public static void printit(int [] a) for (int i = 0; i < a.length; i++) System.out.print(a[i] + " "); System.out.println();

29 11 Lesson 33 - Activity 5 / Term 1: Lesson 33 Coding Activity 5 For the Lesson 33 activities, you will be asked to write one or more methods. Use the template to write a main method that tests each of your methods, then paste everything into the code runner box. Your submission should begin with the first import statement and end with the final. For questions 2-5, you may want to start with the printit method and use it to test the other three. Write a method that takes an array of ints, an integer value, and an integer index.the method should insert the value at the given index and move the values afterwards by one. This method must be called insertvalue() and must have the following parameter types: int[], integer, integer. Calling insertvalue(a, 100, 2) would change the array 1, 2, 3, 4, 5 to 1, 2, 100, 3, 4. / import java.io.; class Lesson_33_Activity_Five public static void insertvalue(int a[], int value, int loc) //This for loop starts at the end of the list and moves //backwards until it reaches loc. for ( int i = a.length - 1; i > loc; i--) //at each step in the loop, we are shifting one element forward //in the array in order to make room for the new value. a[i] = a[i - 1]; //Store the value after shifting the array. a[loc] = value; //main method to test the program. This is not required by the //code runner, but is an important step in writing new methods. public static void main(string [] args) System.out.println("Enter a positive number" + " indicating the length of an array:"); int n = scan.nextint(); int [] a = new int [n]; for(int i = 0; i < n; i++) System.out.println("Enter any integer:"); a[i] = scan.nextint();

30 12 System.out.println("You have entered the array:"); printit(a); System.out.println("Now enter a location:"); int loc = scan.nextint(); System.out.println("And a value to insert:"); int val = scan.nextint(); insertvalue(a, val, loc); System.out.println("After calling insertvalue with" + val + " and " + loc + ":"); printit(a); //include printit for testing public static void printit(int [] a) for (int i = 0; i < a.length; i++) System.out.print(a[i] + " "); System.out.println();

31 13 Lesson 34 - Activity 1 / Term 1: Lesson 34 Coding Activity 1 For the Lesson 34 activities, you will be asked to write one or more methods. Use the template to write a main method that tests each of your methods, then paste everything into the code runner box. Your submission should begin with the first import statement and end with the final. Write a method that takes an array of ints as a parameter and returns the sum of integers in the array. public static int sum(int [] a) For example, sum(a); would return 6, if a = 1, 2, 3, or 3, if a = 1, 1, 1. / import java.io.; class Lesson_34_Activity_One public static int sum(int [] a) //Declare s to store the sum int s = 0; //Loop through the array, adding each value to s for(int i =0; i < a.length; i++) s += a[i]; //return the sum return s; //main method to test the program. This is not required by the //code runner, but is an important step in writing new methods. public static void main(string [] args) System.out.println("Enter a positive number" + " indicating the length of an array:"); int n = scan.nextint(); int [] a = new int [n]; for(int i = 0; i < n; i++) System.out.println("Enter any integer:"); a[i] = scan.nextint(); System.out.println("Calling sum on this array returns " + sum(a));

32 14 Lesson 34 - Activity 2 / Term 1: Lesson 34 Coding Activity 2 For the Lesson 34 activities, you will be asked to write one or more methods. Use the template to write a main method that tests each of your methods, then paste everything into the code runner box. Your submission should begin with the first import statement and end with the final. Write a method that takes an array of ints as a parameter and returns the average value of the array as a double. public static double average(int [] a) For example, average(a) would return 2.0 if a = 1, 2, 3 or 1.0 if a = 1, 1, 1. / import java.io.; class Lesson_34_Activity_Two //Use sum from the previous activity public static int sum(int [] a) int s = 0; for(int i =0; i < a.length; i++) s += a[i]; return s; public static double average(int [] a) //Since we already have a method to sum an array, //we only need to divide that sum by the length. //Multiplying by 1.0 converts sum to a double so that the //result will be accurate. return 1.0 sum(a)/a.length; //main method to test the program. This is not required by the //code runner, but is an important step in writing new methods. public static void main(string [] args) System.out.println("Enter a positive number" + " indicating the length of an array:"); int n = scan.nextint(); int [] a = new int [n];

33 15 for(int i = 0; i < n; i++) System.out.println("Enter any integer:"); a[i] = scan.nextint(); System.out.println("Calling average on this array returns " + average(a));

34 16 Lesson 34 - Activity 3 / Term 1: Lesson 34 Coding Activity 3 For the Lesson 34 activities, you will be asked to write one or more methods. Use the template to write a main method that tests each of your methods, then paste everything into the code runner box. Your submission should begin with the first import statement and end with the final. Write a method that takes an array of ints and returns the largest value in the array. public static int findmax(int [] a) / import java.io.; class Lesson_34_Activity_Three public static int findmax(int []a) //Create a variable to store the max int max = a[0]; for(int i = 0; i < a.length; i++) //if the ith element of a is greater than the max, //then we have a new max, a[i]. if (max < a[i]) max = a[i]; return max; //main method to test the program. This is not required by the //code runner, but is an important step in writing new methods. public static void main(string [] args) System.out.println("Enter a positive number" + " indicating the length of an array:"); int n = scan.nextint(); int [] a = new int [n]; for(int i = 0; i < n; i++) System.out.println("Enter any integer:"); a[i] = scan.nextint(); System.out.println("Calling findmax on this array returns " + findmax(a));

35 17 Lesson 34 - Activity 4 / Term 1: Lesson 34 Coding Activity 4 For the Lesson 34 activities, you will be asked to write one or more methods. Use the template to write a main method that tests each of your methods, then paste everything into the code runner box. Your submission should begin with the first import statement and end with the final. Write a method that takes an array of ints and returns the smallest value in the array. public static int findmin(int [] a) / import java.io.; class Lesson_34_Activity_Four public static int findmin(int []a) //This method is identical to max, //except we reverse the comparison in our //if statement. int min = a[0]; for(int i = 0; i < a.length; i++) if (min > a[i]) min = a[i]; return min; //main method to test the program. This is not required by the //code runner, but is an important step in writing new methods. public static void main(string [] args) System.out.println("Enter a positive number" + " indicating the length of an array:"); int n = scan.nextint(); int [] a = new int [n]; for(int i = 0; i < n; i++) System.out.println("Enter any integer:"); a[i] = scan.nextint(); System.out.println("Calling findmin on this array returns " + findmin(a));

36 18 Lesson 34 - Activity 5 / Term 1: Lesson 34 Coding Activity 5 For the Lesson 34 activities, you will be asked to write one or more methods. Use the template to write a main method that tests each of your methods, then paste everything into the code runner box. Your submission should begin with the first import statement and end with the final. Write a method that takes an array of ints and returns a sum of only the even values. public static int sumeven(int [] a) For example, sumeven(a) would return 6 if a = 1, 2, 3, 4, 5. / import java.io.; class Lesson_34_Activity_Five public static int sumeven(int [] a) //As in the sum method, we need a variable to add values to. int sum = 0; for(int i =0; i < a.length; i++) //An additional if statement is used to only add //even values. if (a[i] %2 ==0) sum += a[i]; return sum; //main method to test the program. This is not required by the //code runner, but is an important step in writing new methods. public static void main(string [] args) System.out.println("Enter a positive number" + " indicating the length of an array:"); int n = scan.nextint(); int [] a = new int [n]; for(int i = 0; i < n; i++) System.out.println("Enter any integer:"); a[i] = scan.nextint(); System.out.println("Calling sumeven on this array returns " + sumeven(a));

37 19 Lesson 34 - Activity 6 / Term 1: Lesson 34 Coding Activity 6 For the Lesson 34 activities, you will be asked to write one or more methods. Use the template to write a main method that tests each of your methods, then paste everything into the code runner box. Your submission should begin with the first import statement and end with the final. Write a method that takes an array of ints and returns true if all of the values in the array are positive. If the array contains any negative integers, it should return false. public static boolean allpositive(int [] a) / import java.io.; class Lesson_34_Activity_Six public static boolean allpositive (int [] a) for(int i = 0; i < a.length; i++) //If a single value is negative, we return false if (a[i] < 0) return false; //If the loop has been run, and we have not returned, then no values //were negative, so we can return true. Students may feel more //comfortable working with a flag variable, but it is worth //discussing this approach to help with understanding //return statements. return true; //main method to test the program. This is not required by the //code runner, but is an important step in writing new methods. public static void main(string [] args) System.out.println("Enter a positive number" + " indicating the length of an array:"); int n = scan.nextint(); int [] a = new int [n]; for(int i = 0; i < n; i++) System.out.println("Enter any integer:"); a[i] = scan.nextint(); System.out.println("Calling allpositive on this array returns " + allpositive(a));