JavaScript 中的函数原型

javascriptweb developmentobject oriented programming更新于 2025/8/30 2:52:17

JavaScript 中创建的函数始终具有 JavaScript 引擎为其添加的原型属性。原型属性是一个默认包含构造函数属性的对象。函数原型可以通过 − 访问

functionName.prototype

当使用函数构造函数创建对象时，此原型属性可用于在该函数构造函数创建的对象之间共享方法或属性。

以下是 JavaScript 中函数原型的代码 −

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;
      color: blueviolet;
   }
</style>
</head>
<body>
<h1>Function prototypes in JavaScript</h1>
<div class="result"></div>
<br />
<button class="btn">点击此处</button>
<h3>Click on the above button to call the welcome method of person1 and person2 object</h3>
<script>
   let resEle = document.querySelector(".result");
   let BtnEle = document.querySelector(".Btn");
   function personConstructor(fName, lName) {
      this.fName = fName;
      this.lName = lName;
   }
   personConstructor.prototype.welcome = function () {
      return "Welcome " + this.fName + " " + this.lName;
   };
   let person1 = new personConstructor("Rohan", "Sharma");
   let person2 = new personConstructor("Shawn", "Smith");
   BtnEle.addEventListener("click", () => {
      resEle.innerHTML = "person1.welcome() = " + person1.welcome() + "<br>";
      resEle.innerHTML += "person2.welcome() = " + person2.welcome() + "<br>";
   });
</script>
</body>
</html>