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JavaScript - Many Arrays Or 1 Array?
I have a choice when creating a new API that I would like other peoples opinions on. Do I use a single Array or Multiple arrays such as:
Code: array[1][1] = "ID[56]NAME[Hello World]START[10]"; OR Code: ID[1][1] = 56; Name[1][1] = "Hello World"; Start[1][1] = 20; The API is used for animations so is very heavy work, but would using around 15 multidimensional arrays be too much and a single one be preferable??? Thanks Similar TutorialsI 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.
/*
Hi I need a bit of javascript help with an array please. just don't seem to have the correct syntax. (the "code" below is pseudo code, just to get the idea across) Here's what I currently have: var bill = new array[20]; var sam = new array[20]; var nancy = new array[20]; var Oscar = new array[20]; I'm assigning objects to them (ie Oscar[5] = new objLabel() This seems like a kluge, however. Here's what I'd like (again, pseudo-code) var Objects = {bill:null; sam:null; nancy:null; Oscar:null}; var theObject = new Array of Objects[20]; // yes: i know that's wrong... and that's the part I'm having trouble with so that I can do something like: with theObject[5] do { bill = new objLabel(); nancy = new objImage(); }; Just seems to me that keeping a single array of multiple objects is likely to be less error-prone than multiple arrays of single objects... But I don't have the syntax right... or can it be done in JS? If it's doable, would someone be kind enough to show me how to declare and access that example? Hi, I'm a JS beginner and I find looping through arrays with for/in is very easy. Yet I find lots of code examples where array length is used instead of for/in and I'm thinking to myself, why do it this (somewhat) hard(er) way? Maybe I'm missing something... Thanks for your help. Hello there, I was having some trouble with 2D arrays (or array of arrays). Essentially, the array has 100 rows, with two columns. The first column of every row holds a name, and the second holds a sales amount. With the use of a do while loop, the user can continuously add up to 100 names and sales amounts. After all the information the user wishes to add is stored into the 2D array I'm attempting to pass that very same 2D array as a parameter to a function called printRow as can be seen in the code below: Note: the function call and the actual function are found in two separate javascripts. Code: var salesPerson=new Array(100)
for (i=0; i <=100; i++)
{
salesPerson[i]=new Array(2);
}
var x = 0;
do
{
salesPerson[x][0] = getName();
salesPerson[x][1] = getSales();
x++;
}while(x != 100 && confirm("Enter more employee information?"));
printRow(salesPerson[][]);
Code: function getName()
{
var nameEntered = prompt("What is your first name?");
return nameEntered;
}
function getSales()
{
var error;
var salesEntered;
do
{
salesEntered = prompt("What were your sales?");
error = false;
if (isNaN(salesEntered) || salesEntered == null || salesEntered == "") error = true;
}while(error);
return salesEntered;
}
function printRow(salesPerson[][])
{
for (i =0; i<salesPerson.length; i++)
{
document.write(salesPerson[i][0] + " " + salesPerson[i][1]);
}
}
At the moment I'm only looking to print the contents of the 2D array that I pass as a parameter to the document. As is, the javascipt doesn't seem to execute at all, it worked fine up until I added the printRow function call and function which leads me to believe I may not be passing it as a parameter correctly. Any tips on how to do this correctly would be greatly appreciated! I apologize in advance for my ignorance. I'm relatively new to javascript. I am trying to dynamically create a page based on information in a .txt. So far the code works. But only for a spacific line in the .txt. I would like it to create numbered divs and fill with approprate info from .txt for each line in .txt. Does that make sense? Any help you can provide would be greatly appriciated. Oh and I'm not worried about cross browser function this is for intra-net and all clients use Mozilla. P.S.: I will paste full code if necessary and it is explained exactly how. Is it: [ "my code goes here" ] or [code] my code goes here [code] I was looking at that old Strawberry Fields problem and I thought I'd see about solving it in JavaScript. What I want is an array of chars so that I can set individual elements in the array of arrays. Strings are apparently immutable and can't directly be changed? Here's my code. Code: var field = new Array();
var string0 = "..@@@@@..............."
var string1 = "..@@@@@@........@@@..."
var string2 = ".....@@@@@......@@@..."
var string3 = ".......@@@@@@@@@@@@..."
var string4 = ".........@@@@@........"
var string5 = ".........@@@@@........"
for (var i = 0; i < 6; i++) {
field[i] = new Array();
field[i] = eval("string" + i + ".slice('')");
}
document.write("field's type is " + typeof field + "<br>"); // object? but it should be explicit array
document.write(typeof field[1]) // string? it should explicitly be an array, then it was filled with array elements
document.write(typeof field[1][2]); // string - ok, I understand this bit
document.write(field[1].length);
document.write("<br>");
for (var i = 0; i < field.length; i++) {
field[i] = new Array();
for (var k = 0; k < eval("string" + i + ".length"); k++) {
field[i][k] = eval("string" + i + ".charAt(" + k + ")");
}
document.write("<br>");
}
document.write("field's type is " + typeof field + "<br>"); // seriously, an object?
document.write(typeof field[1]) // why is this an object instead of an array?
document.write(typeof field[1][2]); // string, yeah, I understand this as well
document.write(field[1].length);
document.write("<br>");
Also, it looks like I can't overwrite a 1-length string that's in the array of arrays. For instance: Code: newField = field; //for loops newField[i][k] = 0; // does nothing, newField's elements remain the same. 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. 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 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! Im working on a program where the user enters a line of numbers and then can either sort them in order or can display the minimum number. Both those seem to work, but for some reason I keep getting three -1 values in my array. So the minimum value is always -1 and when I sort it comes back -1-1-1[numbers i enter]. I cant seem to figure out why my code is doing that. Code:
private int[] buildArray(String line) {
int[]arr = new int[line.length()];
arr[0] = 0;
for (int i = 1; i < line.length(); i++){
arr[i] = Character.digit(line.charAt(i),10);
}
return arr;
}
private int findMin(int numbers[]) {
//PRE numbers.length >= 1
int min = numbers [0];
for (int i = 1; i < numbers.length; i++){
if (numbers [i] < min) {
min = numbers [i];
}
}
return min;
}
private String makeString(int numbers[]) {
//PRE numbers.length >= 1
int i = 0;
String s1 = new String ("");
while (i < numbers.length){
s1 = numbers[i] + s1;
i++;
}
return s1;
}
private void sort(int numbers[]) {
for (int i = 1; i< numbers.length; i++){
int j = i-1;
int temp = numbers[i];
while (j >= 0 && temp > (numbers[j])){
numbers[j+1] = numbers[j];
j--;
}
numbers[j+1] = temp;
}
}
Input: 3,1,2,88 output: Min Value = -1 Line 1 Sorted = -1-1-101288 Any type of help would be very appreciated, Im very new to this still. I have 2 arrays and I would like to compare the 2 arrays. If an element in array 1 is NOT in array 2 then I would like to display that element. In this case, I should only display the letter "c" but it doesn't work and I don't know why?? Here's my code: Code: <html><head>
<script type="text/javascript">
function getValue(id){
var x=new Array("a","b","c","d","e");
var y=new Array("a","b","3","d","e");
var str="";
for (var i=0; i<x.length; i++){
for (var j=0; j<y.length; j++){
if (x[i] == y[j]){
break;
}else{
//Check if reach the last element in the array 2
//If yes, then display that element in array 1 b/c not in array 2
if (y[j] == y.length-1){
str += x[i];
}
}
}
}
document.getElementById(id).innerHTML = str;
}
function init(){
getValue("info");
}
</script>
</head>
<body onload="init()">
<h2 id="info"></h2>
</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. Do arrays retain its data outside of a function. The reason why i asked this is because i created a global array and then a function. In the function i assaigned values to the global array but when i try to access the global array it gives me a "undefined" or "null" error. Code: var myArray = new Array();
var count = 0;
function populate(){
for(i=0; i < 5; i++){
myArray[i] = count++;
}
}
Hi, new to this forum but have a quick question about arrays, I've been working on this all night, and I'm at a loss. I'm trying to calculate the gpa of a user by using arrays and functions. Everything seems to be working besides two things.
The array that contains the class names (className[]) always includes an extra two variables: my sentinel value which is finish, and "undefined"
The arrays at the end won't produce a number when multiplied together. creditData[] and qualityPoints[].
Also, if you have any suggestions on my code, I'd appreciate it. <script type="text/javascript"> <!-- /**************************************************************** ** PrintExplanation - prints a message containing instructions to the user without ** any variable needed. ** Inputs:None ** Outputs:None ****************************************************************/ function PrintExplanation() { alert("This program will calculate your Grade Point Average for any given semester. Please enter only graded classes, no Pass/Fail Classes."); } /**************************************************************** ** GetValidNumberInput - Error checks a number between two constraints. ** Inputs: promptString - allows the user to insert a string in order to be asked. ** lowerNum - the lower constraint you want to be compared. ** upperNum - the higher constraint you want to be compared. ** Outputs: numCredits ****************************************************************/ function GetValidNumberInput(promptString, lowerNum, upperNum) { var promptString; var lowerNum; var upperNum; var numCredits; numCredits=prompt(promptString); while(numCredits<lowerNum || numCredits>upperNum) { numCredits=prompt(promptString); } numCredits=parseFloat(numCredits) return numCredits } /**************************************************************** ** CalculateGPA - Calculates the users GPA ** Inputs: totalCredits: The total amount of credits determined by the user. ** totalQualityPoints: The total amount of quality points determined by the user. ** Outputs: gpa - the users final grade point average. ****************************************************************/ function CalculateGPA(totalCredits, totalQualityPoints) { var totalCredits; var totalQualityPoints; var gpa; gpa=totalQualityPoints/totalCredits return gpa; } function GenerateGPAReport(totalCredits, totalQualityPoints) { } /**************************************************************** ** ConvertGradeToPoints - Converts a letter given by the user into a number corresponding to grade points. ** Inputs: grade - the letter of the grade the student recieved in the course. ** Outputs: points - the number value of the grade that was input by the user. ****************************************************************/ function ConvertGradeToPoints(grade) { var grade; var points; if(grade == "A" || grade== "a") { points=4 } else if(grade == "B" || grade == "b") { points=3 } else if(grade == "C" || grade == "c") { points=2 } else if(grade == "D" || grade == "d") { points=1 } else if(grade == "F" || grade == "f") { points=0 } points=parseFloat(points); return points; } //--> </script> </head> <body> <script type="text/javascript"> var promptString; /*Declares Variables*/ var className; var numOfClasses; var grade; var semester; var numCredits; var lowerNum=1; var upperNum=4; var class1; var i=0; var counter=0; var totalCredits=0; var totalPoints=0; var grade; var counterCredits=0; var counterGrade=0; var points; var gpa; var qualityPoints; var creditData; var gradeData; var x=0; var totalQualityPoints=0; PrintExplanation(); var className = new Array(i); semester=prompt("Please enter the semester you would like to calculate your GPA for."); document.write("Grade report for " + semester + "<br />"); while(class1!="finish") /*Stores the names of the classes taken into an array*/ { class1=prompt("Enter the Class name, or finish to end"); className[i]=class1 i++ } while(counter<=i) /*writes the classes in the array from top to bottom*/ { document.write(className[counter] + "<br />"); counter++ } var creditData = new Array(i) while(counterCredits<=i) /*counts the total number of credits for all the classes*/ { numCredits=GetValidNumberInput("How many credits is " + className[counterCredits] + " class worth?",1,4) creditData[counterCredits]=numCredits totalCredits=totalCredits + numCredits counterCredits++ totalCredits=parseFloat(totalCredits); } var gradeData = new Array(i) /*collects information about grades in an array*/ while(counterGrade<i=) { points=prompt("What grade did you recieve in " + className[counterGrade] + "?"); points=ConvertGradeToPoints(points) gradeData[counterCredits]=points totalPoints=totalPoints+points counterGrade++ } while(x<=i) { qualityPoints=creditData[x]*gradeData[x] totalQualityPoints=totalQualityPoints + qualityPoints x++ } gpa=CalculateGPA(totalCredits, qualityPoints) document.write(gpa); </script> </body> This has been resolved. The moment i posted it i realised the mistake i was making . Learnig how to delete my post, until then thought i would sdimply delete the content.
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? I have a quick question with multiple array and random numbers. If i generate my random numbers in one array, how would i take a selection of those numbers and put them in another array? Ex: array 1: 25, 34, 38, 40, 22, 49 want to move numbers between 30 and 50 to another array. array 2: 34, 38, 40, 49 is it as simple as for loops and if statements setting the conditions? do i use a sorting method? (selection? bubble?) any help would be appreciated. |
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