Create arrays dynamically in a loop with javascript - javascript

Here's a pseudocode example about what I'm trying to do:
var totalLanguages = XX;
for(var i = 0; i < totalLanguages; i++){
var dynamicArray + i = new Array();
/*.....*/
}
I need to create dynamically many arrays as the value of totalLanguages which can be either number.
This is to be able to do something like this:
for(var i = 0; i < totalLanguages; i++){
var arrayLanguages["es"] = dynamicArray+i;
var arrayLanguages["en"] = dynamicArray+i;
}
Is there any way to do this?

var languageNames = ['en', 'es'];
var languages = {};
for (var i = 0; i < languageNames.length; i++) {
languages[languageNames[i]] = [];
}

You are basically trying to recreate an array with variable names. Just use an Array to start out!
var dynamicArray = [];
for(var i = 0; i < totalLanguages; i++) {
dynamicArray[i] = new Array();
}

You can use multi-dimensional arrays:
var languagesArray = new Array(totalLanguages);
for(var i = 0; i < totalLanguages; i++) {
var innerArray = new Array();
innerArray.push("Hello");
innerArray.push("World");
languagesArray[i] = innerArray;
}
console.log(languagesArray[0][0]);
See: How can I create a two dimensional array in JavaScript?

How about:
for(var i = 0; i < totalLanguages; i++){
window["dynamicvariable " + i] = new Array();
/*.....*/
}

Related

Array in php with javascript

I have code like this:
$data = array();
for(int $i = 0; $i < 10; $i ++)
$data[$i][] = 5;
I don't know what's name of $data[$i][] = 5; in php and how to write this code in javascript?
or other hands, how can I write code above in javascript?
Thanks
P/s:
I want to write that code on nodeJs
You can try Array#push to add a element for array
var data = [];
for(var i = 0; i < 10; i ++)
if(!data[i]) data[i] = [];
data[i].push(5);
in this case, can understand $data[$i][] = 5; as below
$data[$i] = array();
array_push($data[$i],5);
// ex: [ 0 => [0 => 5]]
in Javascipt:
var data = [];
for (var i = 0; i < 10; i ++){
data[i] = [];
data[i].push(5);
}
Array.push() is a function used to insert a value into an array. But you can also use the C like way data[i] = 'value'.
data = [];
for (var i = 0; i < 10; i++)
data.push([5]);
document.write(JSON.stringify(data))
As an alternative use
data = [];
for(var i = 0; i < 10; i ++)
data[i] = [5];
document.write(JSON.stringify(data));
Use array.push() to add an item to the end of the array.
var sample = new Array();
sample.push(new Object());
To do this n times use a for loop.
var n = 100;
var sample = new Array();
for (var i = 0; i < n; i++)
sample.push(new Object());
Note that you can also substitute new Array() with [] and new Object() with {} so it becomes:
var n = 100;
var sample = [];
for (var i = 0; i < n; i++)
sample.push({});
JavaScript code:
var data = [];
for (i = 0; i < 10; i++) {
data[i] = [];
data[i][data[i].length] = 5;
}

Initializing the 2D array elements in javascript

I want to initialize and then print the elements of a 2D array using javascript.
I wrote this code but nothing displays as output. How to output this array?
var m = 6;
var n = 3;
var mat = new Array[m][n];
for (i = 0; i < mat.length; i++) {
for (j = 0; j < mat[i].length; j++) {
mat[i][j]) = i * j;
document.writeln(mat[i][j]);
}
document.writeln("<br />");
}
<html>
<body>
</body>
<script>
var m=6;
var n=3;
var mat =new Array(m);
for( var i=0; i < m ; i++){
mat[i] = new Array(n);
for( var j=0;j< n ;j++){
mat[i][j] = i*j;
document.writeln(mat[i][j]);
}
document.writeln("<br />");
}
</script>
</html>
As BenG pointed out, you've got an extra ) but you also aren't initializing your array correctly. Javascript doesn't allow you to declare multi-dimensional arrays like other languages. Instead, you'd have to do something more like this:
var m = 6;
var n = 3;
var mat = new Array(m);
for (var i = 0; i < m; i++) {
mat[i] = new Array(n);
}
Javascript arrays are dynamic. They will grow to the size you require. You can call push() to add a new element to the array. It's also worth noting that you should avoid using the new keyword with objects and arrays. Use their literal notations [] for arrays and {} for objects. So a better solution here would be to push to the arrays as you need them.
var mat = [];
var m = 6;
var n = 3;
for (var i = 0; i < m; i++) {
// Let's add an empty array to our main array
mat.push([]);
for (var j = 0; j < n; j++) {
mat[i].push(i * j);
document.writeln(i * j);
}
document.writeln('<br />');
}

Creating a function to create multiple arrays with the same properties

I want to create multiple arrays that contain the same basic layout. Currently, i have
Array(10); //base array with moving blocks
for(var i = 0; i < 10; i++){ //creating an array within an array (2d)
base[i] = new Array(22);
}
var background = new Array(10); //background array with stationary blocks
for(var z = 0; z < 10; z++){ //same as before
background[z] = new Array(22);
}
var nextBlock = new Array(10); //next block array
for(var i = 0; i <10; i++){
nextBlock[i] = new Array(22);
}
and would like to have something similar to:
function arrayCreator(rows,cols){
var array = newArray(rows);
for(var i = 0;i < rows;i++){
array[i] = newArray(cols);
}
}
var base = arrayCreator(10,22);
var background = arrayCreator(10,22);
var nextBlock = arrayCreator(10,22);
but cant get it working. How should I approach this?
Looks like you forgot the return statement.
function arrayCreator(rows,cols){
var array = newArray(rows);
for(var i = 0;i < rows;i++){
array[i] = newArray(cols);
}
return array;
}

How to make array with string list

I have a generated list which is like this
196-1526, 85-651, 197-1519
I need the array like this. Each node has two part. I need only the first part of each node in one array.
196, 85, 197
I already have this code which generage 196
str.substr(0,str.indexOf('-'));
You could use the following:
'196-1526, 85-651, 197-1519'.replace(/-\d+(,|$)/g, '').split(/\s/)
If the input is a string you can use split() and push(), similar to this:
var x = "196-1526, 85-651, 197-1519"
var y = x.split(',');
var myArray = [];
for(i = 0; i < y.length; i++){
myArray.push(y[i].split('-')[0].trim());
}
DEMO - Using split() and push()
if it's an array
var myarray = ["196-1526", "85-651", "197-1519"];
var newarray = [];
var i = 0;
for(i = 0; i < myarray.length; i++){
var mnode = myarray[i].split("-");
newarray.push(mnode[0].trim());
}
and if it's a string
var myarray = "196-1526, 85-651, 197-1519".split(",");
var newarray = [];
var i = 0;
for(i = 0; i < myarray.length; i++){
var mnode = myarray[i].split("-");
newarray.push(mnode[0].trim());
}
Demo: http://jsfiddle.net/Dbbc8/
try this code using split
var text='196-1526, 85-651, 197-1519';
var splittedtext=text.split(',');
var numbers=new Array();
for(var i=0;i<splittedtext.length;i++)
{
var furthsplit=splittedtext[i].split('-');
numbers[i]=furthsplit[0];
}
alert(numbers);
var pairs = str.split(", ");
var values = [];
for (var i=0; i< pairs.length; i++) {
values.push(pairs[i].substr(0, pairs[i].indexOf('-')));
}

Handling multidimentional array in java script is not working

function split(str)
{
var array = str.split(';');
var test[][] = new Array();
for(var i = 0; i < array.length; i++)
{
var arr = array[i].split(',');
for(var j = 0; j < arr.length; j++)
{
test[i][j]=arr[j];
}
}
}
onchange="split('1,2,3;4,5,6;7,8,9;a,b,c;d,e,f;g,h,i')"
it was not working. i need to split this string to 6*3 multi dimentional array
var array[][] = new Array() is not valid syntax for declaring arrays. Javascript arrays are one dimensional leaving you to nest them. Which means you need to insert a new array into each slot yourself before you can start appending to it.
Like this: http://jsfiddle.net/Squeegy/ShWGB/
function split(str) {
var lines = str.split(';');
var test = [];
for(var i = 0; i < lines.length; i++) {
if (typeof test[i] === 'undefined') {
test[i] = [];
}
var line = lines[i].split(',');
for(var j = 0; j < line.length; j++) {
test[i][j] = line[j];
}
}
return test;
}
console.log(split('a,b,c;d,e,f'));
var test[][] is an invalid javascript syntax.
To create a 2D array, which is an array of array, just declare your array and push arrays into it.
Something like this:
var myArr = new Array(10);
for (var i = 0; i < 10; i++) {
myArr[i] = new Array(20);
}
I'll let you apply this to your problem. Also, I don't like the name of your function, try to use something different from the standards, to avoid confusion when you read your code days or months from now.
function split(str)
{
var array = str.split(';'),
length = array.length;
for (var i = 0; i < length; i++) array[i] = array[i].split(',');
return array;
}
Here's the fiddle: http://jsfiddle.net/AbXNk/
var str='1,2,3;4,5,6;7,8,9;a,b,c;d,e,f;g,h,i';
var arr=str.split(";");
for(var i=0;i<arr.length;i++)arr[i]=arr[i].split(",");
Now arr is an array with 6 elements and each element contain array with 3 elements.
Accessing element:
alert(arr[4][2]); // letter "f" displayed

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