我的定时交通灯程序出了什么问题？ [英] What's going wrong with my timed Traffic Lights program?
本文介绍了我的定时交通灯程序出了什么问题？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我不知道为什么因为它似乎都是正确的并且控制台中没有错误。它总是从green.png开始并停留在那里？我试图制作一个定时的交通信号灯序列，只要页面没有按钮就可以启动。
I don't know why as it seems to be all correct and there are no errors in console. It always starts on green.png and stays there? I'm trying to make a timed traffic lights sequence that can start as soon as the page is loaded without a button.
<!DOCTYPE html>
<html>
<head>
</head>
<body>
<h2>Traffic Lights Program</h2>
<div class="light"><img src="Blank.png" style="width:100px;height:228px;"/></div>
<script>
trafficLight = "green";
var trafficLights = ["Red.png","RedYellow.png","Yellow.png","Green.png"]
function green() {
document.images[0].src = trafficLights[3];
}
function yellow() {
document.images[0].src = trafficLights[3];
}
function redYellow() {
document.images[0].src = trafficLights[1];
}
function red() {
document.images[0].src = trafficLights[0];
}
function yellow2() {
document.images[0].src = trafficLights[2];
}
function automatic() {
if (trafficLight = "green") {
setTimeout(green(),500)
var trafficLight = "yellow";
} else if (trafficLight = "yellow") {
setTimeout(yellow(),500)
var trafficLight = "redYellow";
} else if (trafficLight = "redYellow") {
setTimeout(redYellow(),500)
var trafficLight = "red";
} else if (trafficLight = "red") {
setTimeout(red(),500)
var trafficLight = "yellow2";
} else {
setTimeout(yellow2(),500)
var trafficLight = "green";
}
}
setInterval(automatic(),1000)
</script>
</body>
</html>
推荐答案
/ b>
I've cleaned up your code a bit:
function automatic() {
if (trafficLight == "green") {
setTimeout(green,500);
trafficLight = "yellow";
} else if (trafficLight == "yellow") {
setTimeout(yellow,500);
trafficLight = "redYellow";
} else if (trafficLight == "redYellow") {
setTimeout(redYellow,500);
trafficLight = "red";
} else if (trafficLight == "red") {
setTimeout(red,500);
trafficLight = "yellow2";
} else {
setTimeout(yellow2,500);
trafficLight = "green";
}
}
var interval = setInterval(automatic,1000);
- 不要用
var多次。 - 对于语句使用
==运算符。 - 如果使用命名函数作为处理程序，请不要使用括号
（）。
- Don't redeclare vars with
varmultiple times. - Use the
==operator for statements. - Don't use brackets
()if you using a named function as handler.
这篇关于我的定时交通灯程序出了什么问题？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
查看全文
