网站的流量建设/济南seo顾问
题目：写一个路口红绿灯,现在正对前方是红灯,从20秒开始倒计时,当数值到0时转成绿灯,绿色灯限时20秒,当数值到0时转成黄灯并重新开始倒数3秒,经过3秒的等待,转成红灯20秒,循环往复以上过程
代码：1.1
<body><!-- 写一个路口红绿灯,现在正对前方是红灯,从20秒开始倒计时,当数值到0时转成绿灯,绿色灯限时20秒,当数值到0时转成黄灯并重新开始倒数3秒,经过3秒的等待,转成红灯20秒,循环往复以上过程 --><button>关闭定时器</button><script>// 1.1var time = 43;var time1 = 20;var time2 = 3;var time3 = 20;var timer = setInterval(function() {time--;if (time >= 23) {console.log(('绿灯' + time1 + '秒'));time1--;if (time1 <= 0) {time1 = 20}} else if (time >= 20) {console.log(('黄灯' + time2 + '秒'));time2--;if (time2 <= 0) {time2 = 3}} else if (time >= 0) {console.log(('红灯' + time3 + '秒'));time3--;if (time3 <= 0) {time3 = 20}} else {time = 43;}}, 100)var btn = document.querySelector('button');btn.onclick = function() {clearInterval(timer)}</script>
1.2
<body>
<button>关闭定时器</button><script>var stop = setInterval(a, 100); var count = 30; function a() { count-- ; console.log(count); if (count == 0) { console.log('绿灯到了 '); clearInterval(stop); var count1 = 30; function b() { count1--; console.log(count1); if (count1 == 0) { console.log('黄灯到了 '); clearInterval(stop1); var count2 = 3;function c() { count2--; console.log(count2); if (count2 == 0) { console.log('红灯到了 '); clearInterval(stop2); var count3 = 30;function d() { count3--; console.log(count3); if (count3 == 0) { console.log('绿灯到了 '); clearInterval(stop3); // var count = 8;count = 30; stop = setInterval(a, 100); } } } var stop3 = setInterval(d, 100) } var stop2 = setInterval(c, 100) } } var stop1 = setInterval(b, 100) } }var btn = document.querySelector('button');btn.onclick = function() {clearInterval(stop)}</script>