Question

刚刚遇到这个。它并没有真正影响任何事情，但我想知道它为什么会发生。

如果我在firefox上使用firebug运行以下代码：

setInterval(function(param) 
     {
        console.log("param is %o",param)
     },500);

param似乎被分配了一个模糊的随机值：

   param is -2
    param is -1
    param is -2
    param is 1
    param is -1
    param is 6
    param is -1
    param is 0
    param is -2
    param is 2
    param is 0
    param is 2
    param is 0
    param is 0
    param is 0
[..]
    param is 0
    param is 0
    param is 0
    param is 0
    param is 0
    param is 0
    param is 0
    param is 911
    param is 0
    param is 0
    param is 0
    param is -1

我很感激我没有将任何参数传递给setInterval以传递给函数，但为什么javascript选择传递这个随机数？

我原本期望未定义或类似的东西......

干杯

P.S。尚未在其他浏览器中测试

Answer 1

它似乎依赖于Firefox的CPU使用率。

我猜这是应该调用回调的延迟。

编辑：I was right。这是调用回调后的毫秒数。

Answer 2

这是由window.setInterval自动设置的区间ID。如果存储结果，则可以稍后清除间隔（停止）

var intID = window.setInterval( function(){ alert("I'm annoying!"); }, 10000 );

// this will kill it before it annoys you, :D
window.clearInterval( intID );

window.setTimeout：

的情况也是如此

var timeID = window.setTimeout( function(){ alert("I'm annoying!"); }, 10000 );

// this will kill it before it annoys you, :D
window.clearTimeout( timeID );

奇怪的随机值作为默认间隔处理程序参数

2 个答案: