<html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>let和 var const</title> </head> <body> <button>按钮1</button> <button>按钮2</button> <button>按钮3</button> <button>按钮4</button> <button>按钮5</button> <script> //01 只能在代码块中有效 /* { const li = 'aa'; console.log(li) const li = "cc" console.log(li) }*/ //03 不能重复的申明 //04 申明常量必须赋值 /* let person = '张三', age = 18, sex = '男'; console.log(person)*/ //02 对象结构赋值 /* let [name, sex, age] = ['张三', '男', '18'] console.log(name, sex, age)*/ /* let { name, sex, age, fridends, pet } = { name: '李四', sex: '男', age: 18, fridends: ['张三', '王麻子'], pet: { name: '小花', age: 19 } } console.log(name, sex, age, fridends, pet)*/ //03 数组的结构赋值 // let [name, sex, age] = ['张三', '男', '18'] // let [arr1, [arr2, arr3, arr4, [arr5, arr6]]] = [1, [1, 2, 4, [7, 8]]] // console.log(arr1, arr2, arr3, arr4, arr5, arr6, ) //04 基本类型的结构赋值 let [a, b, d, c, e] = '我是一只猫' console.log(a, b, d, c, e) </script> </body> </html>