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<!DOCTYPE html>
<html>
<body>
<h1>JavaScript 字符串方法</h1>
<p>indexOf() 方法返回指定文本首次出现的位置:</p>
<p id="demo"></p>
<script>
var str = "The full name of China is the People's Republic of China.";
var pos = str.indexOf("China");
document.getElementById("demo").innerHTML = pos;
</script>
</body>
</html>