展开运算符

Tutorial: React基础 Category: React Published: 2026-04-07 13:58:26 Views: 20 Likes: 0 Comments: 0

13_展开运算符

<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8" />
    <title>Document</title>
  </head>
  <body>
    <script type="text/javascript">
      let arr1 = [1, 3, 5, 7, 9];
      let arr2 = [2, 4, 6, 8, 10];
      console.log(...arr1); //展开一个数组
      let arr3 = [...arr1, ...arr2]; //连接数组

      //在函数中使用
      function sum(...numbers) {
        return numbers.reduce((preValue, currentValue) => {
          return preValue + currentValue;
        });
      }
      console.log(sum(1, 2, 3, 4));

      // 构造字面量对象时使用展开语法
      let person = { name: "tom", age: 18 };
      let person2 = { ...person };
      // console.log(...person); //报错, 展开运算符不能展开对象
      person.name = "jerry";
      console.log(person2);
      console.log(person);

      //合并
      let person3 = { ...person, name: "jack", address: "地球" };
      console.log(person3);
    </script>
  </body>
</html>
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