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JavaScript - Newbie Really Needed Help With Arrays And Averages In Js
Hey Coding Forum,
Hey as you probably know iam new here as i probably haven't even posted this in the correct place but i have a real problem with my JavaScript and i can't get it to do what i would like. I have to write a code to show a new array to represent the third row of a table (var myarray value of which are "60","80","187","180","114" , and creating an array of the required length. Which i have done. (i Think ) I now need to write the remainder of the JavaScript needed to calculate the average height of the objects and write it out in the browser window. It need to write average height 17.2 cm. I have included my script below and but i am not understanding how to work out the average, i believe i need to add another 'for loop' but i can't get it to work correctly. (i might be being completely stupid) If anyone would be able to help it would be GREATLY appreciated. Thanks for all help. <HTML> <HEAD> <TITLE> Test Experiment </TITLE> <SCRIPT LANGUAGE = "JavaScript"> var height = [15,16,17,18,19]; var number = [4,5,11,10,6]; var myarray = new Array(5) var myarray = ["60","80","187","180","114"] ; var values = [60, 80, 187, 180, 114]; var total = 0; for ( var i = 0; i < values.length; ++i ) { total += values[i]; } var myarray = total + values.length; document.write('average height of the object is ' +myarray + '<br>'); </SCRIPT> </HEAD> <BODY> </BODY> </HTML> Similar TutorialsI am having some issues with my code... The code is supposed to ask for an average of the values in the numeric property (Cost), which works, but it repeating itself twice. Also, I need to calculate and display the number of elements of (Cost), whose numeric property values is greater than the average. ANY help is highly appreciated ... Thanks! var expense = new Array(); var loop; var property; var numExpense; var LOOP_START = 1; var average = 0; var numberAverage = 0; numExpense=parseInt(prompt("How many expenses?")); for (loop = 0; loop < numExpense; loop++) { expense[loop] = new Object(); } expense[0].Name = prompt("Expense Name?"); expense[0].Cost = parseFloat(prompt("Expense Cost ?")); expense[0].Type = prompt("Expense Type?"); expense[0].Location = prompt("Expense Location?"); for (loop = LOOP_START; loop < numExpense; loop++) { expense[loop].Name = prompt("Expense Name?"); expense[loop].Cost = prompt("Expense Cost?"); expense[loop].Type = prompt("Expense Type?"); expense[loop].Location = prompt("Expense Location?"); } document.write("<br /> <h2> Expenses </h2>"); for(loop = 0; loop < numExpense; loop ++) { for(property in expense[loop]) { document.write("<br />Expense # " + (loop + 1) + " " + property + " : " + expense[loop][property]); } document.write("<br />"); } for(loop = 0; loop < numExpense; loop ++) { for(property in expense[loop]) { average=expense[loop].Cost/numExpense } document.write("<br />Average Cost: $ " + average); } for(loop = 0; loop < numExpense; loop ++) { for(property in expense[loop]) { parseInt(numberAverage) = numExpense > average } document.write("<br />Number of expenses more than Average: $ " + numberAverage); } hi. i know a little php, but new to javascript. much of the syntax is identical. i'm reading the new rhino book (flanagan 6th). in it, where he introduces METHODS, he says "When we combine FUNCTIONS with OBJECTS we get METHODS". Then he creates an empty ARRAY: Code: var a = []; then he uses the "push() method" to add elements to the array. Code: a.push(1,2,3); uh, methods are for *objects* right? Yet he is using them on an ARRAY. Can somebody help me see the light on how an array can magically becomes an object that is manipulated by a "method"? I mean, the array is still an array, no? It never actually becomes an object, right? Yet we still use a *method* to manipulate it. See my conceptual quandry? I have the following code to load iframes but I don't know how to make it load the "LT-video_default.html" when it first loads the page. If I choose one of the options and then go back and choose the "Choose a manufacturer" option it loads the desired page. Here is the code. Code: <script language="JavaScript">
<!-- Begin
function leapto(form) {
var myindex=form.dest.selectedIndex
parent.CONTENT.location.href=(form.dest.options[myindex].value);
// You can output to ANY frame using: parent.[framename].location.href
}
// End -->
</script>
<div id="videoWrapper">
<form name="labtv">
<select name="dest" size="1" onchange="leapto(this.form)">
<option selected="selected" value="LT-video_default.html">Choose A Manufacturer
</option><option value="LT-video_nanodrop.html">NanoDrop
</option><option value="LT-video_bioflux.html">Bioflux
</option><option value="LT-video_genvault.html">GenVault
</option><option value="LT-video_hamilton.html">Hamilton
</option></select>
</form>
<iframe name="CONTENT" frameborder="no" height="400" scrolling="no" width="650">
</iframe>
</div>
Folks I am a newbie to JavaScript. I am basically java/j2ee developer . I want to learn javascript and Ajax . So please let me know what is the latest version of JavaScript , also let me know what book I have to buy ( I mean for the newbie ) Please help me . Thanks in Advance I'm trying to render 14 same sized images on a webpage using a Javascript, I've used in the past, but now can't seem to get it to work. Getting a Syntax Error. On Page http://www.newenglandonline.net/index.fix.html The ERROR appears to be on the following; line 270: var imageDir = ; [CODE] <script type="text/javascript"> (function() { var rotator = document.getElementById(rotator); var imageDir = ; var delayInSeconds = 3; var images = [Cannon_top.jpg,Mount-Washington-Summer.jpg,Mount-Washington-Winter.jpg,Boston_Charles.jpg,Boston_Harbor.jpg,Boston_Harbor_night.jpg,Zakim Bridge.jpg,Edgartown.jpg,GayHeadLighthouse.jpg,HighlandLight.jpg,Newport.jpg,Bridgeport.jpg,Eastpoin tLight.jpg]; var num = 0; var changeImage = function() { var len = images.length; rotator.src = imageDir + images[num++]; if (num == len) { num = 0; } }; setInterval(changeImage, delayInSeconds * 1000); })(); </script> [CODE] Any help or insight will be greatly appreciated. Thanks in advance. Not new to programming but I am to JQuery (and j/script in general). I need to query a mysql database to return a small amount of data (some text) based on a user code (e.g. MrABC). I could use an iFrame and PHP but if the internet connection is down I do not want error messages displayed - the intended audience have limited cognitive capabilities and will not cope with ERROR 404 etc... Essentially I need to be able to create a function that can be called with a parameter of the usercode and which returns the text from the lookup. What I put in the function is a complete mystery to me ... hi i am trying to populate a textarea with the selections like checkboxes radiobuttons textbox combobox but i cant seem to do so. i am naive to the field of programing, and found a few code snippets to do so i tried but it did no good... help needed this is my code " <html> <head> <style type="text/css"> .minitext { font: normal 0.7em Arial, sans-serif; color: Black; } .disable { background-color: #CF110C; color: #fff; font-weight: bold; padding: 5px; } </style> <script language="Javascript" type="text/javascript"> function populateTextArea(){ var output = new Array(); var fieldID = 1; while (fieldObj = document.MyForm['iid'+fieldID]) { if (fieldObj.length) { for (var j=0; j<fieldObj.length; j++) { if (fieldObj[j].checked) { output[output.length] = fieldObj[j].value;} }//end of for } //end of if else { if (fieldObj.checked) { output[output.length] = fieldObj.value; } }//end of else fieldID++; }// end of while document.getElementById('targetarea').value = output.join(', '); //document.MyForm.targetarea.value = document.MyForm.ip1.value + '\n' + document.MyForm.ip2.value + '\n' + document.MyForm.ip3.value ; } </script> </head> <body> <br> <br> <form name="MyForm" method="POST" action="#"> String 1: <input type="text" name="ip1" value=""><br> String 2: <input type="text" name="ip2" value=""><br> String 3: <input type="text" name="ip3" value=""><br><br> <input type="checkbox" name="iid1" id="pe_item2" value="Text string 1"> Text string <input type="checkbox" name="iid1" id="pe_item2" value="Text string 12"> Text string 1<br><br><br> <input type="radio" name="iid2" id="pe_item4" value="Text string 2">Text string 2 <input type="radio" name="iid2" id="pe_item6" value="Text string 3">Text string 3<br> <input type="radio" name="iid3" id="pe_item8" value="Text string 4">Text string 4 <input type="radio" name="iid3" id="pe_item10" value="Text string 5">Text string 5<br> <input type="radio" name="iid4" id="pe_item12" value="Text string 6">Text string 6 <input type="radio" name="iid4" id="pe_item14" value="Text string 7">Text string 7<br> <br> <br> <a href="#" onClick="document.MyForm.targetarea.value = document.MyForm.ip1.value + '\n' + document.MyForm.ip2.value + '\n' + document.MyForm.ip3.value + populateTextArea();" >Populate</a><br> <br> <INPUT TYPE=BUTTON VALUE="Co" ONCLICK= populateTextArea(); > <br> <textarea id="targetarea" name ="targetarea" cols="50" rows="5"></textarea> </form> </body> </html> " help need this done urgently I have my first ever scholastic JS assignment and so far it's felt nearly impossible to get a grip on how to do it. I've gone through the W3c tutorials entirely 3 times now and still, nothing is clicking mentally. Generally I do better if I can reverse engineer already written code but I can't find anything similar enough to this on the net to figure it out. The assignment is to create a grade averages calculator as seen in this pictu Along with this starter code: Code: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Assignments score calculator</title>
<style type="text/css">
<!--
.score {
width: 30px;
}
-->
</style>
</head>
<body>
<h1>Assignments score calculator</h1>
<form id="calculator" name="calculator" method="post" action="">
<p>Enter your Name:
<label for="firstname"></label>
<br />
<input type="text" name="firstname" id="firstname" />
<p>
<label for="A1">Assignment #1 sco </label>
<input name="A1" type="text" class="score" id="A1" maxlength="3" /><br />
<label for="A2">Assignment #2 sco </label>
<input name="A2" type="text" class="score" id="A2" maxlength="3" /><br />
<label for="A3">Assignment #3 sco </label>
<input name="A3" type="text" class="score" id="A3" maxlength="3" />
<p>
<label for="button"></label>
<input type="submit" name="Submit" id="Submit" value="Submit" xx="doCalculation(this.form.firstname.value,this.form.A1.value,this.form.A2.value,this.form.A3.value)" />
</form>
</body>
</html>
I understand what I need to do, just not the syntax to do it. Any help would be appreciated. Sorry for newbiness. I need to loop the alphabet and numbers 0-9 to initialize a few thousand arrays. This is for my site and is truly needed. http://www.thefreemenu.com I currently have every array written out and it takes up to much space in my .js file. The majority of my variables are empty but necessary and need to be there (including empty) for my site to work properly. Question is the last part Here's where I'm at. Code: var NewVarLetterOrNum = "a";
eval("_oneofseveralnames_" + NewVarLetterOrNum + "='this part works';");
alert(_oneofseveralnames_a);
This creates the variable _oneofseveralnames_a='this part works' Code: var newArrayLetterOrNum = "a";
eval("_oneofseveralnames_" + newArrayLetterOrNum + "= new Array();");
alert(_oneofseveralnames_a)
This creates the Array _oneofseveralnames_a=new Array(); and all the values in the array are null, but, now a variable like _nl_a[1]='something' can be used elsewhere because the array exists. This is all that is necessary for now because I can probably set all the variables to be blank with something like Code: i=1
while(i<=20){
_oneofseveralnames_a[i]="1-20";
i++
}
alert(_oneofseveralnames_[20]);
So now you have what I came to understand in the first few hours. Now to the hard part : ( I can't make multiple array's dynamically. I dont' know if its because I don't understand loops or arrays or what and its very fustrating. As for any answer you might be so kind as to provide, if you could dumb it down that would be greatly appreciated. Code: var newArray =new Array('a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z')
i=1
while(i<=26){
eval("_nl_" + newArray[i] + "= new Array();");
i++
}
alert(newArray[1]) // Is b, but
alert(_nl_b) //I can't get _nl_b to exist, I tried everything including taking away the quotes around the letters in every test
*/
var _nl_a =new Array()
var _img_a =new Array()
var _h_a =new Array()
var _r_a =new Array()
var _m_a =new Array()
var _yt_a =new Array()
var _i_a =new Array()
The above arrays are all the array _name_ parts I need but for example, a has 10 parts, a,p2_a,p3_a,.. p10_a. I need 10 pages for each letter of the alphabet and numbers 0-9 and a special all1, p2_all1 ... p10_all1. Overall 2200 arrays that need to be declared. Currently they are all written out.
/*
Code: <HTML>
<HEAD>
<TITLE>Listing 4.4</TITLE>
<SCRIPT TYPE="text/javascript">
//DEFINE METHOD
function displayInfo() {
document.write("<H1>Employee Profile: " + this.data[0] + "</H1><HR /><PRE>");
document.writeln("Employee Number: " + this.data[1]);
document.writeln("Social Security Number: " + this.data[2]);
document.writeln("Annual Salary: " + this.data[3]);
document.write("</PRE>");
}
//DEFINE METHOD TO GET EMPLOYEE INFORMATION
function getInfo() {
var menu="0-Exit/1-Name/2-Emp. #/3-Soc. Sec. #/4-Salary";
var choice=prompt(menu,"0");
if (choice != null) {
if ((choice < 0) || (choice > 4)) {
alert ("Invalid choice");
this.getInfo();
} else {
if (choice != "0") {
this.data[choice-1]=prompt("Enter information","");
this.getInfo();
}
}
}
}
//DEFINE OBJECT
function employee() {
this.data = new Array(4);
this.displayInfo=displayInfo;
this.getInfo=getInfo;
}
newEmployee=new employee();
</SCRIPT>
</HEAD>
<BODY>
<SCRIPT TYPE="text/javascript">
newEmployee.getInfo();
newEmployee.displayInfo();
</SCRIPT>
</BODY>
</HTML>
I am currently taking a Javascript certification course, this is a exercise given (final code) I don't completely understand what is going on though, could someone explain to me Code: this.data[choice-1]=prompt("Enter information","");
that part? I don't understand why, [choice-1] I don't fully understand why an array is even needed here? Hi. I am fairly new to JavaScript. I am having some troubles with arrays. I am using Chrome 12 beta. Here is a brief version of the code I am having trouble with Code: var array=new Array() array[0]=new Array() array[0][1]=new Array() var array[0][1]=[ 3, 1, 4, 1, 5, 9, 2, 6, 5, ... ]; I do not want to use "array[0][1][n]" because my array has too many items to do that and it is just plain annoying to change the numbers that way. I get an error on the "var buffers[0][1]=[" line saying: "Uncaught SyntaxError: Unexpected token [" What is the problem in my code? Thank you ahead of time. ---mint Hi could someone help with this javascript. i dont know where to start with the script which is in bold. Program to report the results of an election. // candidates var candidateArray = ['Mr R Green...', 'Ms O Brown...', 'Ms Y Black...', 'Mr G White...', 'Ms B Grey....','Ms I Blue....', 'Mr V Pink....']; // online votes var onlineVotesArray = [21,47,23,11,56,47,30]; // paper votes var paperVotesArray = [12,4,20,11,5,4,17]; // total votes -- to be initialised below var totalVotesArray; // Add code to // -- initialise totalVotesArray with a new empty array of the same size as candidateArray // -- use a for loop to add the online and paper votes for each candidate and store the result at the corresponding position in the total votes array. First of all thank you for reading my thread and giving time to help me. Here goes my question: How to sort this array? MY PRIORITY COLORS array: ------------ green , yellow ALL COLORS array : <---- this will be your main array. ----------------------- pink , green , orange THE RESULTS: ( the results after you sort) (Not sorted by alphabetically, but sorted by the priority colors) ---------------- green , pink , orange I hope you could help me solve this javascript sorting problem. Thank you! OK first of all I will post some screenshots of the 'website' I have created so far and explain what is working and what is not working. Then I will post my code and ask for help. Below is the main screen before any action happens. The three boxes are DIV elements. The writing and dropdown menu in the first box is generated by Javascript code. Whenever a user selects an option from the dropdown menu. Information about the movie and a picture of the cover are displayed. The movie title, picture filename and movie description are all stored in three separate arrays. Now for the problem. I have created a fourth array "customerList" and left it empty. Whenever a customer clicks the reserve button it calls a function "myReserve()". This function takes the selection from the dropdown menu, then uses the push function to add the selection to the blank array. I then use the code "arrayLength = customerList.length" to get the length of the customer list. A for loop is used to cycle through the array and display the contents of the array. The problem is it only displays one selection. When reserve is clicked again the newest selection is displayed. Why will it not push the next item into the array? Javascript code, just skip through the 3 arrays at the top... the problem function is at the bottom. Code: var movieTitles = new Array(8)
movieTitles[0] = "The Prestige [2006]"
movieTitles[1] = "The Lives of Others [2007]"
movieTitles[2] = "The Bourne Ultimatum [2007]"
movieTitles[3] = "Spider-Man 3 [2007]"
movieTitles[4] = "Casino Royale [2006]"
movieTitles[5] = "The Illusionist [2006]"
movieTitles[6] = "Sunshine [2007]"
movieTitles[7] = "Zodiac [2007]"
movieTitles[8] = "Quantum of Solace [2008]"
var movieCovers = new Array(8)
movieCovers[0] = "prestige.jpg"
movieCovers[1] = "lives_of_others.jpg"
movieCovers[2] = "bourne3.jpg"
movieCovers[3] = "spiderman3.jpg"
movieCovers[4] = "casinoroyal.jpg"
movieCovers[5] = "illusionist.jpg"
movieCovers[6] = "sunshine.jpg"
movieCovers[7] = "zodiac.jpg"
movieCovers[8] = "quantum_of_solace.jpg"
var movieDescriptions = new Array(8)
movieDescriptions[0] = "Two Victorian-era magicians develop a rivalry that builds into an escalating battle of tricks."
movieDescriptions[1] = "Five years before its downfall, the former East-German government ensured its claim to power with a ruthless system of control and surveillance."
movieDescriptions[2] = "Legendary assassin Jason Bourne uncovers mysteries of his past, which puts him in the cross-hairs of a superkiller."
movieDescriptions[3] = "When Peter Parker's suit suddenly turns black it brings out the dark, vengeful side of his personality."
movieDescriptions[4] = "The story examines James Bond's first mission after getting his licence to kill."
movieDescriptions[5] = "Eisenheim is a stage magician who amazes the audiences of turn-of-the-century Vienna, drawing the attention of Crown Prince Leopold."
movieDescriptions[6] = "Fifty years from now, the sun is dying, and mankind is dying with it. Our last hope: a spaceship carrying a device which will breathe new life into the star."
movieDescriptions[7] = "A serial killer terrifies the San Francisco Bay Area and taunts police with his ciphers and letters."
movieDescriptions[8] = "Seeking revenge for the death of his love, secret agent James Bond sets out to stop an environmentalist from taking control of a country's water supply."
var customerList = new Array()
function getMovieTitle()
{
var str = "<p>Available movies are contained in the list below.<br />Select a movie title to read more details.<br />If you want to add the movie to your list click the reserve option.<br /></p>"
str = str + "<form action='P4_1.html' method='post'><select onChange = 'displayMovie()' name='title' id = 'droplist'><option>Choose a movie</option>"
mylength = movieTitles.length
//loop for each movie title in the movieTitles array
for (var i=0; i<mylength; i++)
{
str = str + "<option>" + movieTitles[i] + "</option>"
}
str = str+"</select></form>"
//place content into dropdown menu
document.getElementById("dropdown").innerHTML = str
}
function displayMovie()
{
var i
i = document.getElementById('droplist').selectedIndex - 1
var m = movieTitles[i]
m = m + "<p><br><img src='"+movieCovers[i]+"'></p>"
m = m + movieDescriptions[i]
m = m + "<p> <a href='Javascript:myReserve()'><span id = 'res'> Reserve </span></a></p>"
document.getElementById("Movie_Info").innerHTML = m
}
function myReserve()
{
var i
i = document.getElementById('droplist').selectedIndex - 1
customerList.push(movieTitles[i])
arrayLength = customerList.length
for (var j=0; j<arrayLength; j++)
{
str = customerList[j]
}
document.getElementById("Movie_List").innerHTML = str
}
HTML code, incase you want to create my files yourself to troubleshoot for me but all the problems occur in the myReserve function just above. Everything else works fine. Code: <html xmlns:mso="urn:schemas-microsoft-com:office:office" xmlns:msdt="uuid:C2F41010-65B3-11d1-A29F-00AA00C14882"> <head> <title>P4_1</title> <script src="P4.js" type="text/javascript"></script> <link rel="stylesheet" type="text/css" media="screen" href="P4.css" /> <!--[if gte mso 9]><xml> <mso:CustomDocumentProperties> <mso:ContentType msdt:dt="string">Document</mso:ContentType> </mso:CustomDocumentProperties> </xml><![endif]--> </head> <body onload="javascript:getMovieTitle()"> <img src="logo.jpg"> <div id="dropdown" class="box1"> </div> <div id="Movie_Info" class="box2"> <p>Movie info will go here</p> </div> <div id="Movie_List" class="box3"> <p>Your movie list will go here</p> </div> </body> </html> Got this script from the Sam's Teach Yourself Javascript In 24 Hours book, and I'm a little confused with regards to this script I came across, or more specifically, the part of the script I've outlined in red. Code: <script language="javascript" type="text/javascript">
function numcompare(a,b) {
return a-b;
}
nums = new Array (17, 902, 30, 10, 200, 4, 506);
sortednums = nums.sort(numcompare);
output = sortednums.join(", ");
document.write(output);
</script>
I really don't understand how the numcompare() function works, and the book doesn't explain it very well. Any help with deciphering this piece of code? Thanks in advance. Hashim. I am working on making 2 for loops of 2 arrays to get the total of them. Then I need to get the average heights. This is for a test, yet I have not got a clue, so I need clues as I cant get it to work and I am a new coder to javascript. Code: var heights = [15,16,17,18,19];
var numbers = [2,1,6,4,2];
var average = new Array(5);
average = 0
for (var heights = 0; heights <= 5; heights = heights+ 1)
{
total = 0
}
for (var numbers = 0; numbers <= 5; numbers = numbers + 1)
{
total = 0
average = heights / numbers;
}
document.write('The average height is ' + average);
Am I on the right road? I need to use this format and not functions. I have got 2 for statements but maybe I could do this with one, it is so tricky this javascript. If anyone is planning on buying "ICAB4225B Automate Processes" in relation to a TAFE/College/School course, I suggest getting the teacher to actually READ the book before they use it. Tonight has been a HE-Double Hockeysticks (Not sure on language in this forum) of fixing mistakes the book has made. Double commars inplace of singles, singles inplace of doubles, single brackets, whole chunks of text that are wrong. In one place in the book it tells me to copy the text in blod and there is none. Anyway.... The code that the book has made me piece together over the last few questions has left me with: Code: <script type = "text/javascript">
{
var counter = 0
var NoOfItems
var ItemsNames = new Array()
NoOfItems = prompt ("How many items do you want to hock?","");
for (NameCount=0; NameCount<NoOfItems; NameCount++)
{
ItemNames [NameCount] = prompt ("What are the names of your items?","");
}
document.write ("<form name='myform'><br><table>");
while ( counter < NoOfItems)
{
document.write ("<tr><td><value>Enter the price of the " + ItemNames [count] + "</td><td><input type='text' name='" + ItemNames [count] + "'></td></tr>");
counter++
}
document.write ("<tr><td><input type='submit' value='Submit Details' onClick='validateform'</td></tr></table></form>");
}
</SCRIPT>
The problem I am having it with the Array. I dont think that var = new Array is correct but thats what my text book is telling me. Any help? Hey, I'm working on a problem and what I need the program to do is to add up the numbers in the array NOT add up how many numbers there are. There are 5 total numbers that a user will input. The counting of the numbers will be in a seperate method which will then return to the main. Then be displayed through system.out.println. I don't know where I am going wrong any help? Thanks! Code:
import javax.swing.*;
import java.util.*;
public class Question10 {
public static void main (String []args) {
//declares
Scanner keyboard = new Scanner(System.in);
int [] myNums = new int[5];
for (int i=0; i < myNums.length; i++) {
System.out.println ("Please Enter Data");
myNums[i]= keyboard.nextInt();
}
} //end main
public static int getTotal(int inArray) {
int a,b,c,d,e,f;
f = a+b+c+d+e;
return f;
}
}//end class
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