javascript一些方法兼容

标签（空格分隔）： javascript 方法收集

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Object.keys

参考地址

if (!Object.keys) Object.keys = function(o) {

  if (o !== Object(o))

    throw new TypeError('Object.keys called on a non-object');

  var k=[],p;

  for (p in o) if (Object.prototype.hasOwnProperty.call(o,p)) k.push(p);

  return k;

}

throttle

让函数必须间隔多少时间执行，函数节流,在movemove等需要一停执行进有用，再比如window.resize

function throttle(fn,delay) {

    var timer = null;

    var t_start;

    delay = delay||200;

    return function() {

        var context = this,t_curr = +new Date();

        if(!t_start) {

            t_start = t_curr;

        }

        var args = arguments;

        if(t_curr - t_start <delay) {

            clearTimeout(timer);

            timer = setTimeout(function(){

                fn.apply(context,args);

            },delay)

        }else {

            fn.apply(context,args);

            t_start = t_curr;

        }

    }

}