debounce&throttle.js

$.debounce = function(fn, time, ctx) {
    var ret = 0;
    if( typeof time !== 'number' ) {
      ctx = time;
      time =  50;
    }
    time = time || 50;
    return function() {
      var args = [].slice.apply(arguments);
      // 注意是ctx的问题
      // 错误写法：ctx = ctx || this,这样写ctx会被改变
      var nctx = ctx || this;
      clearTimeout(ret);
      ret = setTimeout(function() {
        fn.apply(nctx, args);
      }, time);
    }
  }
  /**
   * throttle 操作
   */
  $.throttle = function(fn, time, ctx) {
    if( typeof time !== 'number' ) {
      ctx = time;
      time =  50;
    }
    time = time || 50;
    var isLocked = false;
    var isThrottleBeigin = false;

    return function() {
      var args = [].slice.apply(arguments);
      var nctx = ctx || this;
      if(!isThrottleBeigin){
        setInterval(function(){isLocked = false;},time);
        isThrottleBeigin = true;
      }
      if( !isLocked ) {
        isLocked = true;
        fn.apply(nctx, args);
      } 
    }
  }
  
  //throttle 函数修改版
  $.throttle = function(fn, time, ctx) {
  if( typeof time !== 'number' ) {
    ctx = time;
    time =  50;
  }
  time = time || 50;
  var isLocked = false;
  return function() {
    var args = [].slice.apply(arguments);
    var nctx = ctx || this;
    var timer;
    if( !isLocked ) {
      isLocked = true;
      fn.apply(nctx, args);
      timer = setTimeout(function(){isLocked = false;},time);
    }
  }