Sort Objects by field - JS

sort-obj-by-field.js

// My own implementation of merge sort (by object field)
var a = [
    {name: "Mr. Burns", age: 145},
    {name: "Moe", age: 37},
    {name: "Apu", age: 39},
    {name: "Carl", age: 34},
    {name: "Homer Simpson", age: 38},
    {name: "Marge Simpson", age: 36},
    {name: "Lisa Simpson", age: 12},
    {name: "Bart Simpson", age: 34},
    {name: "Maggie Simpson", age: 2},
    {name: "Krusty", age: 35}
];

function mergeSort(input, field){
    var splitted = [];
    for(var i = 0; i < input.length; i++){
        splitted.push([input[i]]);
    }

    var merged = (function merge(arr){
        var tempResult = [];
        for( var i = 0; i < arr.length; i+=2 ){
            var left = 0,
                right = 0,
                result = [],
                current = i,
                next = i+1;

            // for odd arrays, if doesn't has next then it's odd therefore need to push the current array
            if( !arr[next] ){
              tempResult.push(arr[current]);
            }
            else{
              while( left < arr[current].length || right < arr[next].length ){
                  
                  // case there's only one element remaining (odd number of elements)
                  if( (left === arr[current].length
                      && right < arr[next].length) ){
                      result.push(arr[next][right]);
                      right++;
                      continue;
                  }
                  else if( left < arr[current].length
                      && right === arr[next].length ){
                      result.push(arr[current][left]);
                      left++;
                      continue;
                  }

                  var val1 = arr[current][left][field];
                  var val2 = arr[next][right][field];

                  if( val1 < val2 ){
                      result.push(arr[current][left]);
                      left++;
                  }
                  else{
                      result.push(arr[next][right]);
                      right++;
                  }
              }
              tempResult.push(result);
            }
        }
        if( tempResult.length > 1 ) return merge(tempResult);
        else return tempResult;

    }(splitted));

    return merged[0];
}
// start timer
console.time('mergeSort');
// sort by age
var sortedArray = mergeSort(a, 'age'); // can be sorted by 'name' or other field existing in the obj
console.timeEnd('mergeSort');
console.log(sortedArray);