Chapter 11 Paper Practice

Size: px

Start display at page:

Download "Chapter 11 Paper Practice"

Bruno Nicholson
5 years ago
Views:

1 Chapter 11 Paper Practice Scrambled Code For each method, rearrange the lines of code in order to build the functionality required by the specification and tests. To accomplish this, you are given three things: 1) The javadoc specification of Paper 2) The JUnit tests for Paper 3) The code for each method with the lines scrambled Your task is to put the lines of each method into an order that will meet the specification and make the tests pass.

2 Javadoc Specification Package Class Use Tree Deprecated Index Help PREV CLASS NEXT CLASS FRAMES NO FRAMES All Classes SUMMARY: NESTED FIELD CONSTR METHOD DETAIL: FIELD CONSTR METHOD Class Paper java.lang.object Paper public class Paper extends java.lang.object A sequence of silly methods that compute things about numbers, arrays, and Strings Author: Merlin Field Summary Constructor Summary Paper() Method Summary int biginventory(int numengines, java.lang.string trucks) Calculate the number of big wheels our parts department should have on hand to repair broken wheels. boolean isprime(int num) Computes whether a given number is prime

3 int numberofwheels(java.lang.string trucks) Train engines are labeled by the number of wheels in each truck (group of wheels) it contains. boolean sumisodd(int num) Computes the sum of the digits in a number and returns true if that sum is an odd number Methods inherited from class java.lang.object clone, equals, finalize, getclass, hashcode, notify, notifyall, tostring, wait, wait, wait Field Detail Constructor Detail Paper public Paper() Method Detail sumisodd public boolean sumisodd(int num) Computes the sum of the digits in a number and returns true if that sum is an odd number Parameters: num - the number we are to work with Returns: true if the sum of the digits is odd isprime public boolean isprime(int num) Computes whether a given number is prime Parameters: num - the number we are checking Returns: true if num is prime

4 numberofwheels public int numberofwheels(java.lang.string trucks) Train engines are labeled by the number of wheels in each truck (group of wheels) it contains. For example, a engine has three trucks that contain 2, 4, and 2 wheels, respectively. Given an engine description, this method will compute the number of wheels the engine has. Parameters: trucks - An engine description which will contain 3 or 4 trucks where each truck has between 2 and 8 wheels Returns: the total number of wheels on the engine. biginventory public int biginventory(int numengines, java.lang.string trucks) Calculate the number of big wheels our parts department should have on hand to repair broken wheels. We need to have 10% of the number of wheels that are in service. The center trucks have big wheels while the first and last trucks have small wheels. Parameters: numengines - the number of engines that are in service trucks - An engine description Returns: the number of big wheels that we should have in our inventory. SInce we can't keep partial wheels, we should always round up. skip- navbar_bottom Package Class Use Tree Deprecated Index Help PREV CLASS NEXT CLASS FRAMES NO FRAMES All Classes SUMMARY: NESTED FIELD CONSTR METHOD DETAIL: FIELD CONSTR METHOD

5 JUnit Tests: import static org.junit.assert.*; import org.junit.test; * Tests for a set of silly methods * Merlin public class PaperPracticeTest * Test if the sum of the digits of a number is public void oddsums() Paper p = new Paper(); asserttrue(p.sumisodd(1235)); assertfalse(p.sumisodd(12346)); assertfalse(p.sumisodd(2)); asserttrue(p.sumisodd(7)); * Tests for primality. Make sure that two public void testprime() Paper p = new Paper(); asserttrue(p.isprime(17)); assertfalse(p.isprime(8)); asserttrue(p.isprime(2)); * Test Strings of various sizes to make sure we count the * number of wheels in a train engine public void testtrains() Paper p = new Paper(); assertequals(8, p.numberofwheels("2-4-2")); assertequals(14, p.numberofwheels("4-4-6")); assertequals(14, p.numberofwheels(" "));

6 * Tests for calculating our big wheel inventory. The * cases test when we have to round up and when we public void testbigwheels() Paper p = new Paper(); assertequals(3, p.biginventory(6, "2-4-2")); assertequals(8, p.biginventory(10," "));

7 #1 num = num / 10; return sum % 2 == 1; int sum = 0; while (num > 0) sum = sum + num % 10; * Computes the sum of the digits in a number and returns * true if that sum is an odd number * num * the number we are to work with true if the sum of the digits is odd public boolean sumisodd(int num)

8 #2 if (num % i == 0) return true; for (int i = 2; i < num / 2; i++) return false; * Computes whether a given number is prime * num * the number we are checking true if num is prime public boolean isprime(int num)

9 #3 int sum = 0; return sum; sum = sum + trucks.charat(i) - '0'; while (i < trucks.length()) int i = 0; i = i + 2; * Train engines are labeled by the number of wheels in * each truck (group of wheels) it contains. For example, a * engine has three trucks that contain 2, 4, and 2 * wheels, respectively. Given an engine description, this * method will compute the number of wheels the engine has. * trucks * An engine description which will contain * 3 or 4 trucks where each truck has between 2 * and 8 wheels the total number of wheels on the engine. public int numberofwheels(string trucks)

10 #4 return totalwheels/10; return (totalwheels/10+1); if (trucks.length() == 5) if (totalwheels%10 == 0) wheelsperengine = trucks.charat(2)-'0'; else wheelsperengine = trucks.charat(2) + trucks.charat(4)-2*'0'; int totalwheels = wheelsperengine*numengines; int wheelsperengine; else * Calculate the number of big wheels our parts department * should have on hand to repair broken wheels. * We need to have 10% of the number of wheels that are in * service. The center trucks have big wheels while * the first and last trucks have small wheels. numengines the number of engines that are in service trucks An engine description the number of big wheels that we should have in our * inventory. Since we can't keep partial wheels, we * should always round up. public int biginventory(int numengines, String trucks)

/** * Tests for a class that converts scores to letter grades Merlin * */ public class PaperTest {

/** * Tests for a class that converts scores to letter grades Merlin * */ public class PaperTest { Here is a test class and you are going to write the class it tests. At the end of the tests, you ll find the javadocs for the class you are creating. You can use them to more fully understand the methods