Nodejs Array Sort sortBy()

Method Source Code

Array.prototype.sortBy = function() {
      function _sortByAttr(attr) {
          var sortOrder = 1;
          if (attr[0] == "-") {
              sortOrder = -1;/*from   w w  w.  j  av a 2 s  . com*/
              attr = attr.substr(1);
          }
          return function(a, b) {
              var result = (a[attr] < b[attr]) ? -1 : (a[attr] > b[attr]) ? 1 : 0;
              return result * sortOrder;
          }
      }
      function _getSortFunc() {
          if (arguments.length == 0) {
              throw "Zero length arguments not allowed for Array.sortBy()";
          }
          var args = arguments;
          return function(a, b) {
              for (var result = 0, i = 0; result == 0 && i < args.length; i++) {
                  result = _sortByAttr(args[i])(a, b);
              }
              return result;
          }
      }
      return this.sort(_getSortFunc.apply(null, arguments));
}

Related

1. sortAscending()

   Array.prototype.sortAscending = function() {
     return this.sort( function( a, b ) {
       if ( a > b ) {
         return 1;
       return a < b ? -1 : 0;
     } );
   };
   

2. sortAscending()

   Array.prototype.sortAscending = function() {
     this.sort(function(a, b) {
       return a - b;
     });
     return this;
   };
   var largestProductOfThree = function(array) {
     array = array.slice().sortAscending();
     var secondFromLast = array[array.length - 2];
   ...
   

3. sortBool(iteratee)

   Array.prototype.sortBool = function(iteratee) {
       var _iteratee = function(a, b) {return iteratee(a, b) ? -1 : 1};
       return this.sort(_iteratee);
   };
   

4. sortBy( field, ascending_order )

   Array.prototype.sortBy= function( field, ascending_order ) {
     var asc = ascending_order ? 1 : -1;
     return this.sort(function (a, b) {
            return (asc *(a[field] <= b[field]) ? -1:1);
     });
   };
   

5. sortBy(()

   Array.prototype.sortBy = (function() { 
       function identity(v){return v;} 
       function ignoreCase(v){return typeof(v)==="string" ? v.toLowerCase() : v;} 
       function makeCompareFunction(f, opt){ 
           opt = typeof(opt)==="number" ? {direction:opt} : opt||{}; 
           if(typeof(f)!="function"){ 
               var prop = f; 
               f = function(v1){return !!v1[prop] ? v1[prop] : "";} 
           if(f.length === 1) { 
               var uf = f; 
               var preprocess = opt.ignoreCase?ignoreCase:identity; 
               f = function(v1,v2) {return preprocess(uf(v1)) < preprocess(uf(v2)) ? -1 : preprocess(uf(v1)) > preprocess(uf(v2)) ? 1 : 0;} 
           if(opt.direction === -1) return function(v1,v2){return -f(v1,v2)}; 
           return f; 
       return function(callbacks){ 
           var array = this; 
           function tb(func, opt) { 
               var x = typeof(this) == "function" ? this : false; 
               var y = makeCompareFunction(func, opt); 
               var f = x ? function(a, b) { 
                               return x(a,b) || y(a,b); 
                         : y; 
               f.thenBy = tb; 
               f.sort = () => array.sort(f); 
               return f; 
           return tb(callbacks); 
       }; 
   })();
   

6. sortBy(comparator)

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

7. 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;
       });
   };
   ...
   

8. 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
     })
   

9. 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{
   ...