先看以下两看计时器
setInterval
function sleep(time) { ?let startTime = window.performance.now(); ?while (window.performance.now() - startTime < time) {}}function test(){ ???count++; ???console.log(`第${count}次开始 ${getTime.now() - startTime}`); ????// 显示开始时间 ???//sleep(100); // 程序滞留500ms ???console.log(`第${count}次结束 ${getTime.now() - startTime}`); // 显示结束时间 ???count>1000 && clearInterval(t);}let count = 0;let getTime = window.performance;let startTime = getTime.now();var t = setInterval(test , 500); // 300ms间隔最后结果：
再来看下setTimeout
function sleep(time) { ?let startTime = window.performance.now(); ?while (window.performance.now() - startTime < time) {}}function test(){ ?console.log(`第${count}次开始 ${getTime.now() - startTime}`); // 显示开始时间 ?//sleep(500); // 程序滞留500ms ?console.log(`第${count}次结束 ${getTime.now() - startTime}`); // 显示结束时间 ?count += 1; ?if(count<1000){setTimeout(test,500);}}var startTime0 = new Date().getTime();let count = 0;let getTime = window.performance;let startTime = getTime.now();var t;//setTimeout(test,500); // 300ms间隔setTimeout(function () { ?console.log(`第${count}次开始 ${getTime.now() - startTime}`); // 显示开始时间 ?//sleep(500); // 程序滞留500ms ?console.log(`第${count}次结束 ${getTime.now() - startTime}`); // 显示结束时间 ?count += 1; ?var offset = new Date().getTime() - (startTime0 + count * 500); ???var nextTime = 500 - offset;//console.log(nextTime); ???if (nextTime < 0) nextTime = 0; ???if(count<200){setTimeout(arguments.callee, nextTime);} ???????????????????}, 500)js定时器优化
原文地址：https://www.cnblogs.com/7qin/p/10225220.html