JavaScript 中的点符号与方括号符号


点符号和方括号符号都用于访问 JavaScript 中的对象属性。点符号用得较多,因为它更便于阅读和理解,而且啰嗦的成分也更少。点符号和方括号符号之间的主要区别在于,方括号符号允许我们使用变量来访问对象属性。

以下是 JavaScript 中方括号符号与点符号的代码 −

示例

 实时演示

<!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;
      color: blueviolet;
   }
</style>
</head>
<body>
<h1>Dot notation vs Bracket notation in JavaScript</h1>
<div class="result"></div>
<button class="Btn">CLICK HERE</button>
<h3>Click on the above button to access the student1 object properties using dot and bracket notation</h3>
<script>
   let resEle = document.querySelector(".result");
   let BtnEle = document.querySelector(".Btn");
   function Student(name, age, standard) {
      this.name = name;
      this.age = age;
      this.standard = standard;
   }
   let student1 = new Student("Rohan", 18, 12);
   BtnEle.addEventListener("click", () => {
      let str = "name",
      str1 = "age",
      str2 = "standard";
      resEle.innerHTML ="Using dot notation <br>student1.name = " + student1.name +       "<br>";
      resEle.innerHTML += "student1.age = " + student1.age + "<br>";
      resEle.innerHTML +=
      "student1.standard = " + student1.standard + "<br><br>";
      resEle.innerHTML +=" Using bracket notation <br>student1[str] = " +
      student1[str] +"<br>";
      resEle.innerHTML += "student1[str1] = " + student1[str1] + "<br>";
      resEle.innerHTML += "student1[str2] = " + student1[str2] + "<br>";
   });
</script>
</body>
</html>

输出

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更新日期:2020 年 7 月 20 日

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