解释 JavaScript 中的 String.trimStart() 和 String.trimEnd() 方法

javascriptweb developmentobject oriented programming更新于 2025/8/21 8:12:17

String.trimStart() 方法用于从字符串开头删除空格，而 String.trimEnd() 方法用于从字符串末尾删除空格。

以下是 String.trimStart() 和 String.trimEnd() 方法的代码 −

示例

<!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,.sample {
      font-size: 20px;
      font-weight: 500;
   }
</style>
</head>
<body>
<h1>String.trimStart() and String.trimEnd() methods</h1>
<div&g;<pre class="sample"></pre></div>
<div style="color: green;"><pre class="result"></pre></div>
<button class="btn">点击此处</button>
<h3>
Click on the above button to trim the above string from start and end
</h3>
<script>
   let resEle = document.querySelector(".result");
   let sampleEle = document.querySelector(".sample");
   let str = " HELLO WORLD ";
   sampleEle.innerHTML = str;
   document.querySelector(".Btn").addEventListener("click", () => {
      resEle.innerHTML = "trimStart() :" + str.trimStart() + "|<br>";
      resEle.innerHTML += "trimEnd() :" + str.trimEnd() + "|";
   });
</script>
</body>
</html>