Lab 2 Population. Purpose. Assignment Lab 2 analyzes population growth of a town as well as compare the population growth of two towns.

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Maurice Golden
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1 Lab 2 Population Purpose To assess your ability to apply the knowledge and skills developed up though week 7. Emphasis will be placed on the following learning outcomes: 1. Decompose a problem into modularized components. 2. Write and call function(s) that utilize parameters and return values. 3. Write correct selection 'if', 'if/else' or ternary operator statements to solve a given problem. 4. Write correct iteration 'for', 'do-while' or 'while' statements to solve a given problem. 5. Perform validation of input data. Assignment Lab 2 analyzes population growth of a town as well as compare the population growth of two towns. For population growth of a town, the program receives the population, projected population growth rate, and number of years. It display the population in a table form. See the sample out. (A sample input is: Population of town A = 10000, growth rate of town A = 5%, and number of years = 10.) For population comparison between two towns, the program receives the population of town A, population of town B, projected population growth of town A and projected growth of town B. The program outputs population of each town until population of town A is greater than the population of town B. (A sample input is: Population of town A = 10000, growth rate of town A = 5%, population of town B = 20000, and growth rate of town B = 2%.) Create a program that prompts the user to choose either population growth of a town of population of analysis of two towns. Validate the input values. The program output will be in the form of an HTML table. See the sample outputs. Your submission must demonstrate your solution in action. Each ZIP file should contain at least one HTML and JS file all in the same folder. Do not duplicate code, use functions to avoid this common issue in programming. Action Items/Programming Requirements The solution must use and deliver both an HTML and a JS file. The JS file must be referenced in the <head> tag of the HTML document using the <script> tag to load your function so it can be called later on. The solution should use a <script> in the <body> of the HTML to call the main population function. The prompt() function must be used to all gather information from the user just as was done in the example screen shots. Do not use <input> tags or hard coded input values. Declare local variables only. No global variables permitted. All JS files must use the strict directive at the top of the file. Strict declarative will allow the JavaScript Console in a browser to display an error for undeclared variables.

2 Follow the input-process-output program model. You should have at least these functions. o The main population function gets user input on which type of population analysis and call the appropriate population function to do the work. Make sure to validate the input. See the sample output. o Population of one town (popofonetown) function for one town/city population analysis. This function should prompt for user inputs, validate the inputs, create the HTML table, and display the result. The input values must meet the following criteria: Population is positive number. Projected population is a number. It could be positive or negative number. Number of years is a positive number. o Population of two town (popoftwotowns) function for two towns population analysis. This function should prompt for user inputs, validate the inputs, create the HTML table, and display the result. The input values must meet the following criteria: Town A population is positive number Town b population is positive number Town A population is less than town B. Town A growth rate is greater than town B. o You should create functions that generates the HTML table for population analysis. You would need two such functions, one for popofonetown function and one for popoftwotown function. These functions will build a string that contains the HTML code for the table of results and use the return statement to return this string to the function caller. Put the HTML and JS files in the same folder. Try to make your solution look similar to the screen shots. Put identifying information in your files: your name, assignment name/number term/class. Example for HTML:  Example for JS: /** YourName * Lab FA-ITEC 136 */ Don t forget to comment each function with function prolog. Review code against the documentation and style requirements Word document available on the course web site for the assignment. You will find that both documentation and style requirements are facilitated by the Aptana Integrated Development Environment (IDE).

3 Screen Shots (FireFox): Population of one town

4 Population of two towns:

7 Here are some invalid inputs examples. These are not comprehensive. See the programming requirements for more details. Invalid type: Invalid population

8 Town A population is larger than town B Town A growth rate is smaller than town B

9 Helpful Hints The following hints may help you to solve the problem: The JavaScript file must have "use strict"; directive. Use the prompt() function to input data. For example: var favcolor = prompt("what is your favorite color?", "yellow ); The first parameter is shown to the user and the second parameter is the optional default response. Recall that prompt() returns a string value. Use the parsefloat() function to convert a string into a floating point number. After the JavaScript below, receipttotal will hold a floating point value with decimal precision, ready to be used in math operations. Likewise, num variable can have decimal value. var numberasstring = "6.023"; var receipttotal = parsefloat(numberasstring); var num = parsefloat(prompt("what is 5 / 2?")); Use the parseint() function to convert a string into an integer number. After the JavaScript below, totalpeople will hold a whole number value of 123, ready to be used in math operations. Likewise, age variable only hold integer value. var totalpeopleasstring = "123"; var totalpeople = parseint(totalpeopleasstring); var age = parseint(prompt("how old are you?")); Use input validation loop to validate each input. Use the following code snippet as example on how to create a string containing the HTML table, var result = "<table border='1'><tr><th>col 1</th><th>Col 2</th></tr>"; result += "<tr>"; result += td(col1_data); result += td(col2_data); result += "</tr>"; Use the tofixed() method of any Number object (variable) to convert a number into a string with a fixed number of decimal places. For example: var mypi = ; document.writeln(mypi.tofixed(4)); // writes out Use Math.round() to round a number to the nearest integer var wholenum = Math.round(20.49); // Returns 20 var temp = Math.round(50.63); // Returns 51 Use document.writeln() to display output to user.

10 Grading Criteria Quality of the solution: 0 50 points o Documentation (internal comments) (0 5 points) It is not uncommon for industry to impose a way of documenting software that is uniform across all programmers. Documentation standards are outlined in the same document referenced in the style bullet below. o o Style (formatting, naming conventions and appearance of solution code) (0 5 points) As listed in the action items of the course web page lab assignment, ensure that your solution code meets the documentation and style guidelines for this course. The documentation and style requirements Word document titled "DocumentationAndStyleGuidelines.doc exists in the Resources folder on your course CD and as a link on the lab assignment page web page. Review your code against this document. I am looking for consistency also. For example, if you prefer to put your curly braces on the same line as the if statement rather than the next line, that is fine provided you are consistent throughout your code. Correctness (how the program works under test) (0 40 points) The program should work, and be seen to work. The code should be robust. Note that grammar, spelling, and writing mechanics do not contribute to the total points for this assignment; however, improper grammar, poor spelling, or poor writing mechanics may result in significant point deductions.

Lab 1. Purpose. Assignment. Action Items/Programming Requirements

Lab 1. Purpose. Assignment. Action Items/Programming Requirements Lab 1 Purpose To assess your ability to apply the knowledge and skills developed in weeks 1 through 4. Emphasis will be placed on the following learning outcomes: 1. Create and display simple syntactically