merge sort js

merge_sort.js

l = console.log

l("\n\nstart:")
function merge(left, right){
    l("merge: l: " + left + ", r: " + right);
    var result = [],
        il = 0,
        ir = 0;

    while (il < left.length && ir < right.length){
        if (left[il] < right[ir]){
            result.push(left[il++]);
        } else {
            result.push(right[ir++]);
        }
    }

    return result.concat(left.slice(il)).concat(right.slice(ir));
}

function mergeSort(items){

    if (items.length < 2) {
//        l("return: " + items);
        return items;
    }

    var middle = Math.floor(items.length / 2),
        left = items.slice(0, middle),
        right = items.slice(middle);
        
    l("mergeSort: left: " + left + ", right: " + right);
        
    var params = merge(mergeSort(left), mergeSort(right));
        
    l("\nafter merge: " + params);
    
  
    return params;
}


l(mergeSort([3,10,2,5,22,6,9,20]))