Move an array element from one array position to another

Question

I\'m having a hard time figuring out how to move an array element. For example, given the following:

var arr = [ \'a\', \'b\', \'c\', \'d\', \'e\'];
<         


        

Answer 1

I ended up combining two of these to work a little better when moving both small and large distances. I get fairly consistent results, but this could probably be tweaked a little bit by someone smarter than me to work differently for different sizes, etc.

Using some of the other methods when moving objects small distances was significantly faster (x10) than using splice. This might change depending on the array lengths though, but it is true for large arrays.

function ArrayMove(array, from, to) {
    if ( Math.abs(from - to) > 60) {
        array.splice(to, 0, array.splice(from, 1)[0]);
    } else {
        // works better when we are not moving things very far
        var target = array[from];
        var inc = (to - from) / Math.abs(to - from);
        var current = from;
        for (; current != to; current += inc) {
            array[current] = array[current + inc];
        }
        array[to] = target;    
    }
}

http://jsperf.com/arraymove-many-sizes