Nodejs Array Sort sortBy(keySelector)

Method Source Code

Array.prototype.sortBy = function (keySelector) {
    return this.slice().sort(function(a,b) {
        var aKey = keySelector(a),
            bKey = keySelector(b);/*from w  w w  .  j a va  2s . c o  m*/
        
        if (aKey > bKey) {
            return 1;
        }
        else if (bKey > aKey) {
            return -1;
        }
        else {
            return 0;
        }
    });
};

Array.zip = function(left, right, combinerFunction) {
    var results = [];
    
    for(var counter = 0, len = Math.min(left.length, right.length); counter < len; counter++) {
        results.push(combinerFunction(left[counter], right[counter]));
    }
    
    return results;
};

Related

1. sortBy()

   Array.prototype.sortBy = function() {
         function _sortByAttr(attr) {
             var sortOrder = 1;
             if (attr[0] == "-") {
                 sortOrder = -1;
                 attr = attr.substr(1);
             return function(a, b) {
                 var result = (a[attr] < b[attr]) ? -1 : (a[attr] > b[attr]) ? 1 : 0;
   ...
   

2. sortBy(comparator)

   Array.prototype.sortBy = function(comparator) {
       return this.sort((a,b) => {
           return comparator(a) < comparator(b) ? -1 : 1
       })
   

3. sortBy(f)

   Array.prototype.sortBy = function (f) {
       return this.sort(function (a, b) {
           if (a[f] < b[f])
               return -1;
           if (a[f] > b[f])
               return 1;
           return 0;
       });
   };
   ...
   

4. sortBy(field, direction)

   Array.prototype.sortBy = function (field, direction) {
     var asc = direction === 'asc'
     return this.sort(function (a, b) {
       if (a[field] < b[field]) return asc ? 1 : -1
       if (a[field] > b[field]) return asc ? -1 : 1
       return 0
     })
   

5. sortBy(index,sort)

   Array.prototype.sortBy = function(index,sort){
       index = index || 0;
       sort = sort || "asc";
       var i, j, t, len = this.length;
       for(i = 0 ; i < len ; i ++){
           for(j = 1 ; j < len ; j++){
               if(this[j].charCodeAt(index >= 0 ? index : this[j].length+index) > this[j-1].charCodeAt(index >= 0 ? index : this[j-1].length+index)){
                   if(sort === "asc"){
                   }else{
   ...
   

6. sortBy(p)

   Array.prototype.sortBy = function(p) {
     return this.slice(0).sort(function(a,b) {
       return (a[p] > b[p]) ? 1 : (a[p] < b[p]) ? -1 : 0;
     });
   };
   

7. sortBy(p, type)

   Array.prototype.sortBy = function(p, type) {
     if(type == undefined) type = "asc";
     if(type == "desc"){
       return this.slice(0).sort(function(a,b) {
         return (a[p] < b[p]) ? 1 : (a[p] > b[p]) ? -1 : 0;
       });        
     } else {
       return this.slice(0).sort(function(a,b) {
         return (a[p] > b[p]) ? 1 : (a[p] < b[p]) ? -1 : 0;
   ...
   

8. sortByDesc(f)

   Array.prototype.sortByDesc = function (f) {
       return this.sort(function (a, b) {
           if (a[f] < b[f])
               return 1;
           if (a[f] > b[f])
               return -1;
           return 0;
       });
   };
   ...
   

9. sortByFrequency()

   Array.prototype.sortByFrequency = function () {
     var freq = {};
     this.map(function(e, i, a){
       if(e in freq){
         freq[e]++;
       } else {
         freq[e] = 1;
     });
   ...