Question

Im trying to find simplest way to merge two arrays into the third one, with jQuery, like this:

[A,B,C,D]
[1,2,3,4]

The answer would be:

[A,1,B,2,C,3,D,4]

Another example:

[A,B,C] + [1,2,3,4,5] = [A,1,B,2,C,3,4,5]
[A,B,C,D] + [1,2,3] = [A,1,B,2,C,3,D]

Answer 1

You can directly create an Array using the jQuery.map()^[docs] method. When you return an Array, jQuery.map does a .concat().

This will also prevent holes in the Array when lengths differ.

http://jsfiddle.net/zbCj7/

var chars = ['A','B','C','D'];
var nums = [1,2,3,4];

var res = $.map( chars.length > nums.length ? chars : nums, function(v,i) {
    var chr = chars[i];
    var num = nums[i];
    if( chr !== undefined && num !== undefined ) {
        return [chr,num];
    } else if( chr === undefined ) {
        return num;
    } else {
        return chr;
    }
});

or a little more concise:

http://jsfiddle.net/zbCj7/1/

var chars = ['A','B','C','D'];
var nums = [1,2];

var res = $.map( chars.length > nums.length ? chars : nums, function(v,i) {
    var chr = chars[i];
    var num = nums[i];
    return ( chr !== undefined && num !== undefined ) ?
        [chr,num] : ( chr === undefined ) ? num : chr;
});

---

If you really want to make it concise, you could do this:

http://jsfiddle.net/zbCj7/2/

var chars = ['A','B','C','D'];
var nums = [1,2];

var res = $.map( chars.length > nums.length ? chars : nums, function(v,i) {
    return [ chars[i], nums[i] ].slice( chars[i]===undefined,
                                        nums[i]===undefined || 2 );
});