add-remove-members.js

《JavaScript精粹》 源文件下载

// Please note: this file contains snippets for comparison
// it is not self-contained or ready-to-use code as such

var planets = ['mercury', 'venus', 'earth'];
planets.push('mars', 'jupiter');
alert(planets);

planets = ['mercury', 'venus', 'earth', 'mars', 'jupiter'];
planets.splice(2, 2);
alert(planets);

planets = ['mercury', 'mars', 'jupiter'];
planets.splice(1, 0, 'venus', 'earth');
alert(planets);

planets = ['mercury', 'venus', 'earth', 'saturn'];
planets.splice(0, 3, 'mars', 'jupiter');
alert(planets);

var planets = ['mercury', 'venus', 'earth'];
planets[planets.length] = 'mars';
alert(planets);


Array.prototype.push = function()
{
  for (var i = 0; i < arguments.length; i++)
  {
    this[this.length] = arguments[i];
  }
  return arguments[i - 1];
};
Array.prototype.splice = function(a, b)
{
  var tmp = [];
  for (var i = a + b; i < this.length; i++)
  {
    tmp[tmp.length] = this[i];
  }

  var rem = [];
  for (i = a; i < a + b; i++)
  {
    rem[rem.length] = this[i];
  }

  this.length = a;

  for (i = 2; i < arguments.length; i++)
  {
    this[this.length] = arguments[i];
  }

  for (i = 0; i < tmp.length; i++)
  {
    this[this.length] = tmp[i];
  }

  return rem;
};