Question

当我运行此代码时，它最初无法找到源 ＆＃34; src =＆＃34; color [var x]＆＃34; ＆＃34; 但是一旦我使用了colourChange它就可以了，我只需要解决这个问题。任何帮助将非常感激。

非常感谢

src=[var x]

Answer 1

html元素属性src="colour[var x]"中没有Javascript变量。因此，您必须使用有效路径值初始化src，或者您可以在js中初始化它

...
var colour = ["red.gif", "amber1.gif", "green.gif", "amber1.gif"];
document.getElementById("light").src = colour[0];
function colourChange(){
...

Answer 2

喜欢这个

＆＃13;

<!DOCTYPE html>
<html>
<head>
<title>Traffic Lights</title>
</head>
<body>

<img id="light" src="https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcSeIlyurWoqEAMds0DmsxrFDr0R3bXCErkDAWGEnuUF757qN7uW" width="150px" height="150px">
<button onclick="colourChange()">Click Me To Cycle Through The Colours</button> 
<script>
var x=0;
var colour = ["https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcSeIlyurWoqEAMds0DmsxrFDr0R3bXCErkDAWGEnuUF757qN7uW", "https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcQ7t30uQ_C4eV-HXMFZU2EPlqQ_MwsMA2kEfkzBFjC3Sav4OM3n", "https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcSNxgGXA3G2NwGVo70gZmy3ccYEcOSo4vzcPsgQRLbU_hGIBCWrnA", "https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcSqFHvDm74NYMdbBtW-ZO9o3irXu4GHynOkDiCxDXJ484m1Ahyt"];
function colourChange(){
     x += 1;
    document.getElementById("light").src = colour[x];
    
    if (x == 3) x = 0;
}
</script>

</body>
</html>

＆＃13;

Varibla图像源问题

2 个答案: