arrays.js

function arrCollection() {
  this.createArray = function(len) {
    var ret = [];
    for(var i = 0; i < len; i++) {
      ret.push(i);
    }
    return ret;
  };
  this.reduceToPrime = function(arr) {
    var ret = arr.filter(function(value) {
      var isPrime = function(value) {
          var divisor = 2;
          while (value > divisor) {
            if (value % divisor === 0) {
              return false;
            }
            divisor++;
          }
          return true;
      };
      console.log(isPrime(value), value);
      return isPrime(value) === true;
    });
    return ret;
  };

}

Array.prototype.remove = function(index) {
  var ind = this.indexOf(index);
  this.splice(index, 1);
};

var myArray = new arrCollection();

var bigArr = myArray.createArray(100);

bigArr.remove(0);
console.log(bigArr);
var smallerArr = myArray.reduceToPrime(bigArr);
console.log(smallerArr);