labs.arrayWhere.js

/*!
Written for education purpose. 
Could use Array.filter / Array.map instead.

Example: 

    //Returns an array with one object: {name:'foo'}
    var result = { packages : [{name:'foo'}, {name:'bar'}, {name:'baz'}] };
    result.packages.where(function() { 
        var name = this.name;
        return name && name.match(/fo/g);
    });

    //Returns an array of even numbers: [2,4,6] 
    [1,2,3,4,5,6].where(function() {
        return this % 2 === 0;        
    });

*/
(function() {
  'use strict';
  Array.prototype.where = Array.prototype.where || function(predicate) { 
      var results = [];
      if (typeof predicate !== 'function') {
          return results;
      }

      var len =  this.length,  
          i = 0;

      while (i < len) {
          var item = this[i++];
          if (predicate.call(item)) {
              results.push(item);
          }
      }   

      return results; 
  };
}());