JavaScript WITH 语句有哪些用途?
WITH 语句用于指定给定属性的默认对象,并允许我们防止编写冗长的对象引用。它将给定对象添加到作用域链的头部。
以下是 JavaScript 中 with 语句的代码 −
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 { font-size: 20px; font-weight: 500; } </style> </head> <body> <h1>JavaScript with statement</h1> <div style="color: green;" class="result"></div> <button class="Btn">CLICK HERE</button> <h3>Click on the above button to get the first and lastname property of obj</h3> <script> let resEle = document.querySelector(".result"); let BtnEle = document.querySelector(".Btn"); let obj = { firstName: "Rohan", lastName: "Sharma", }; BtnEle.addEventListener("click", () => { with (obj) { resEle.innerHTML = "Welcome " + firstName + " " + lastName; } }); </script> </body> </html>
输出
以上代码将产生以下输出 −
单击“点按此处”按钮 −
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