<!DOCTYPE html>
<html>
<body>
<div class="example">First div element with class="example".</div>
<div class="example">Second div element with class="example".</div>
<p>Click the button to change the text of the first div element with class="example" (index 0).</p>
<button onclick="myFunction()">Try it</button>
<p><strong>Note:</strong> The getElementsByClassName() method is not supported in Internet Explorer 8 and earlier versions.</p>
<script>
function myFunction() {
var x = document.getElementsByClassName("example");
x[0].innerHTML = "Hello World!";
}
</script>
</body>
</html>
鏈接,例如:http://www.w3schools.com/jsref/tryit.asp?filename=tryjsref_document_getelementsbyclassname如何返回2個值與getElementsByClassName()?
這個例子告訴我們如何改變第一個div來的 「Hello World」。我想學習我如何將所有課程改爲「Hello world」。我試圖將x[0].innerHTML = "Hello World!";
更改爲x[*].innerHTML = "Hello World!";
,但沒有發生任何事情。任何想法? :/
它可能是重複的,但提問者似乎並不明白他需要循環... –