javaScript to return a new array of paired values from an array of single values [duplicate]

Question

Possible Duplicate:
Split array into chunks

I am trying to convert an array of values into a new array of paired values.

For example i need to convert:

var arr = [1,2,3,4,5,6,7,8];

into:

arr = [[1,2], [3,4], [5,6], [7,8]];

I tried using jQuery's .map() method like so but this did not work for me:

arr= $.map(arr, function(n, i){
return [n + ',' + n[ i + 1 ]];
});

Answer 1

If you insist on using map, you could do it like this:

arr= $.map(arr, function(n, i){
    if (i%2 === 0) return [[n, arr[ i + 1 ]]];
});

Answer 2

If you don't want to use a hammer on a thumbtack:

var arr = [1,2,3,4,5,6,7,8];

var newarr = new Array();

for (var i=0; i<arr.length; i=i+2) {
    newarr.push(arr.slice(i,i+2));
}

Answer 3

don't use jquery for every problem:

var arr = [1, 2, 3, 4, 5, 6, 7, 8];
var narr = [];
for (i = 0; i < arr.length; i = i + 2) {
    narr[i / 2] = [arr[i], arr[i + 1]];
}

but this only works if you have an even count of arr