js中计时器怎么暂停

function Timer(callback, delay) {

var timerId, start, remaining = delay;
//暂停
this.pause = function() {
    window.clearTimeout(timerId);
    remaining -= new Date() - start;
};
//继续
this.resume = function() {
    start = new Date();
    window.clearTimeout(timerId);
    timerId = window.setTimeout(callback, remaining);
};

this.resume();

}

var timer = new Timer(function() {

alert("Done!");

}, 1000);

timer.pause();
// Do some stuff...
timer.resume();

先创建定时器，拿到定时器句柄，再清楚该定时器

1. 单次定时

// 创建定时器， 仅一秒后执行一次
var timer = setTimeout(function(){ console.log('something') }, 1000)

// 清除定时器
clearTimeout(timer)

1. 循环定时

// 创建定时器, 每秒执行一次
var timer = setInterval(function(){ console.log('something') }, 1000)

// 清除定时器
clearInterval(timer)