Introduction to Computer Science - Java Script Programming | CMSI 182, Assignments of Computer Science

Download Introduction to Computer Science - Java Script Programming | CMSI 182 and more Assignments Computer Science in PDF only on Docsity! CMSI 182 I N T R O D U C T I O N T O C O M P U T E R S C I E N C E Fall 2006 Assignment 1026 This assignment caps off our XHTML exploration by integrating it with the JavaScript programming lan- guage. This is a recurring theme in computer science — “interoperability” among multiple technologies. For Submission We start by interacting with the JavaScript scratch page on the course Web site, after which it will be your turn to make a full XHTML page + JavaScript program from scratch. Training Wheels: JavaScript Scratch Page Modify the first two programs that you wrote in Assignment 0921 (i.e., converting inches to centi- meters and calculating the average of n numbers) so that the input values for these programs are de- rived from the entry fields of the JavaScript scratch page on the course Web site. In both cases, have your program use Input 1 for the user’s input. • For the inches-to-centimeters conversion pro- gram, you will need the built-in parseFloat() func- tion to convert the text that the user enters into a number that can be used for calculations. • For the average of n numbers, have the user en- ter the numbers as a comma-separated list (e.g., “8, 12, 30, 40, 48, 29, 22”). Then, use the built-in split() method to convert this single piece of text into an array of separate items (e.g., “8,” “12,”, “30,” etc.). Finally, you will need the parseFloat() again in order to convert the text into numbers. To use split() correctly, invoke it this way: var numberText = input1.value.split(", "); This will give back an array (see the Operating Sys- tems handout and the midterm) consisting of the individual text items without the commas. Then, you can loop through this array in a manner simi- lar to how we have done our sample “batch op- erating system” programs (handout, midterm). Down the Rabbit Hole: Page and Program Adapt the third program from Assignment 0921 — “make change” — into a complete XHTML + JavaScript combination: • Create an XHTML page with a form that holds one text input field, labeled “Make Change for:” (refer to your October 19 notes as well as the JavaScript scratch page itself for pointers). • Include a “Make Change” button in the form as well, such that clicking on this button will display, below the form (and not as an alert), the number of quarters, dimes, nickels, and pennies that are needed for the amount entered by the user. • You will need the built-in parseInt() function to convert the user’s text into a number. • As a reminder, recall that the steps to designate a section of your Web page that can be modified by your JavaScript program are: 1. Create a span with an id attribute. <span id="output"></span> 2. To modify the content of this span, use the getElementById() method on the built-in docu- ment object then set its innerHTML property. document.getElementById("output"). innerHTML = /* Result goes here. */; How to Turn it In Do the assigned work electronically, then: 1. E-mail the code and XHTML file to me, and 2. Submit hardcopy versions of these items. Turn these in by the October 26 class. Extra Credit Look up and learn how to use the for-in loop (it looks like for (var i in array) { }) and use that in- stead of while in the average calculation program. Extra Extra Credit Allow the “make change” program to have custom- ized coin denominations — that is, let the user modify the available set of coins with which to make change. For example, instead of the “25, 10, 5, 1” set that we use, the user might want to make change with “20, 15, 3, 2, 1” denominations.