复制代码 代码如下:

var num = 0;

var max = 10;

function incrementNumber() {

num++;

//if the max has not been reached, set another timeout

if (num < max) {

setTimeout(incrementNumber, 500);

} else {

alert(“Done”);

}

}

setTimeout(incrementNumber, 500);

如果用setInterval 可能出现 下次调用会在前一次调用前调用 （

True intervals are rarely used in production environments because it ' s possible that one interval will begin before the previous one has finished executing）