所谓解构，指的是将数据结构分解为更小的部分，从而使数据提取变得容易。

对象解构：

• 使用解构时，必须提供初始化值

      let Person = {
          name: 'sen',
          age: 18
      }
      let {name, age} = Person;
  

• 解构表达式的值为=右侧的值
• 如果对象中没有同名属性时，解构表达式新赋值的变量的值为undefined
• 解构对象只是赋值时，需要加()
• 赋值给不同名的变量

      let Person = {
          name: 'sen',
          age: 18
      }
      let {name: localName, age: localAge} = Person;
  

• 设置默认值

      let Person = {
          name: 'sen',
          age: 18
      }
      let {name, age: localAge = 18} = Person;
  

• 嵌套解构

      let Person = {
          name: 'sen',
          age: 18,
          score: {
              maths: 100
          }
      }
      let {name, score: {maths}} = Person;
      console.log(maths);
  

数组解构

•     let score = [99, 88, 77];
      let [maths, english, chinese] = score;
      [,,chinese] = score;
  

• 数组解构赋值不需要加()

      let a = 3;
      let b = 4;
      [a, b] = [b, a]
  

• 嵌套的解构

      let score = [99, 88, [77]];
      let [,,[chinese]] = score;
  

• 剩余项

      let score = [99, 88, 77];
      let [maths, ...restScore] = score;
      console.log(restScore) // [88, 77]
  

• 数组和对象可以混合解构

      let Person = {
          name: 'sen',
          age: [0, 18]
      }
      let {name: localName, age: [start]} = Person;
      console.log(start);