Javascript Multidimensional array

Question

I am trying to push the values [100,1000,10000,200,2000,20000,300,3000,30000] inside the multidimensional array in Javascript.

Multidimensional array should look like below

[[100,1000,10000],[200,2000,20000],[300,3000,30000]]

I am using the below code

var j = 0;
var x = 0;
var z = 0;
var f = new Array();
var rows = [100, 1000, 10000, 200, 2000, 20000, 300, 3000, 30000];
for (var i = 1; i <= rows.length; i++) {
 if (j < i) {
 f[x] = new Array();
 var arrval = parseInt(rows[j]);
 f[x][z] = arrval;
 z++;
 if (i % 3 == 0) {
 x++;
 z = 0;
 }
 j++;
 }
}

But the push into multidimensional array push seems to be not working. The final output is looking like [[,,10000],[,,20000],[,,30000]]

Could you please help?

Thanks in advance

Answer 1

Try this:

 var rows = [100, 1000, 10000, 200, 2000, 20000, 300, 3000, 30000];
 var newarr = new Array();
 /*for(var i =0; i< rows.length; i++){
 newarr.push(rows.splice(0,3));
 }
 console.log(newarr);*/
 while(rows.length){
 newarr.push(rows.splice(0,3)); 
 }

You can even make a function that would receive the number of columns as parameters.

function(orArr, nArr, cols){
 for(var i =0; i< orArr.length; i++){
 nArr.push(rows.splice(0,cols));
}

Update

: You should actually use slice() instead of splice() . as your original array would be modified if you are using splice(); In that case your code would be:

var newarr = new Array();
for(var i =0; i< rows.length; i++){
 newarr.push(rows.slice(0,3));
}
console.log(newarr);

Answer 2

You are clearing f[x] each iteration!

Here is a fix :)

var rows = [100,1000,10000,200,2000,20000,300,3000,30000];
var x=0; var z=0; var f = new Array();
for (var i=1;i<=rows.length;i++) {
 if(!f[x]){
 f[x]=new Array();
 };
 f[x][z]=parseInt(rows[i-1]);
 z++;
 if(i%3==0)
 {
 x++;
 z = 0;
 }
}

Answer 3

Here's another way to do it with a single loop http://jsfiddle.net/rene3/

var f = [];
var rows = [100, 1000, 10000, 200, 2000, 20000, 300, 3000, 30000];
for (var i = 0, len = rows.length; i < len ; i++) {
 if( !(i%3) ){
 f.push([]);
 }
 f[Math.floor(i/3)].push(rows[i])
}

Answer 4

var f = [];
f.push([[100,1000,10000],[200,2000,20000],[300,3000,30000]]);

if there should be a dynamic loop, you could try:

var f = [];
var MyVal = n; // n = any value you like
var Val100, Val1000, Val10000;
for (var i=1; i<MyVal+1; i++){
Val100 = i*100;
Val1000 = i*1000;
Val10000 = i*10000;
f.push([Val100,Val1000,Val10000]);
}

Answer 5

var f = new Array(),
 x = 0,
 rows = [100, 1000, 10000, 200, 2000, 20000, 300, 3000, 30000];
for (var i = 0; i < rows.length; i++) {
 var a;
 if (i % 3 == 0) {
 f[x] = new Array();
 a = f[x];
 x++;
 }
 a.push(rows[i]);
}

http://jsfiddle.net/3R35Q/