解释 JavaScript 中正则表达式的“dotAll”标志
dotAll 标志会返回 true 或 false,具体取决于正则表达式中是否设置了 s 标志。
以下是 JavaScript 中用于实现正则表达式 dotAll 标志的代码 −
范例
<!DOCTYPE html>
<html lang="en" >
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Document</title>
<style>
body {
font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
}
.result {
font-size: 20px;
font-weight: 500;
}
</style>
</head>
<body>
<h1>dotAll flag for regular expressions</h1>
<div style="color: green;" class="result"></div>
<button class="btn">CLICK HERE</button>
<h3>
Click on the above button to know if s flag has been set in regex or not
</h3>
<script>
let btnEle = document.querySelector(".btn");
let resEle = document.querySelector(".result");
const regex = new RegExp("Hello", "s");
btnEle.addEventListener("click", () => {
resEle.innerHTML = "The s flag has been set : " + regex.dotAll;
});
</script>
</body>
</html>输出
上述代码将生成以下输出 −

点击“单击此处”按钮 −

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