Array.remove. Remove item from array via index. Array.trim. Delete from index start to end.

array.prototypes.js

// remove item from array via index
Array.prototype.remove = function(index) {
  if (this.indexOf(index) !== -1) {
    this.splice(index, 1);
  }
  return this;
};

// remove `from` to `to` items
Array.prototype.trim = function(from, to) {
  var rest = this.slice((to || from) + 1 || this.length);
  this.length = from < 0 ? this.length + from : from;
  return this.push.apply(this, rest);
};