javascript - setTimeout 的使用不正确？

Question

我编写了一个脚本，它根据一些随机数逻辑触发 2 个 URL，我试图在触发其中一个 URL 之前设置一个延迟(半秒)，但我认为它无法正常工作。我这样做正确吗？代码如下:

var clicks  = "http://www.urlone.com";
var impressions = "http://www.urltwo.com";
var randomNumber = (Math.random()*100);

function callOut() {
for (var i = 0; i < lengthVal; i++){
    if (randomNumber < 75) { 
        var randomCounter = (Math.random()*100);
            if (randomCounter < 50) {
                setTimeout("image1.src = clicks;",500);

            }
            else if (randomCounter > 50) {
                setTimeout("image1.src = impressions;",500);                    
            }
    }
    }
}

Answer 1

setTimeout 第一个参数应该是一个函数。不是代码串。

code in the alternate syntax, is a string of code you want to execute after delay milliseconds. (Using this syntax is not recommended for the same reasons as using eval())

MDN

setTimeout(function(){...}, 500);