1. [let和const两个关键字与var之间有哪些不同？](https://github.com/pwstrick/daily/issues/102)
2. [请说明一下const的特点。](https://github.com/pwstrick/daily/issues/103)
3. [扩展运算符（...）的用途有哪些？](https://github.com/pwstrick/daily/issues/104)
4. [剩余参数有什么作用？](https://github.com/pwstrick/daily/issues/105)
5. [什么是解构？](https://github.com/pwstrick/daily/issues/106)
6. [如果忽略声明关键字，那么在运行对象解构的时候，为何要用圆括号包裹赋值表达式（如下所示）？](https://github.com/pwstrick/daily/issues/107)
```javascript
({ a, b } = { a: 3, b: 4 });
```
7. [如何利用数组解构交换变量？](https://github.com/pwstrick/daily/issues/108)
8. [执行[, , z] = [1, 2, 3]后，z的值为__________。](https://github.com/pwstrick/daily/issues/109)
9. [执行[x, ...y] = [1, 2, 3]后，x的值为__________，y的值为__________。](https://github.com/pwstrick/daily/issues/110)
10. [执行({ a: e, a: f } = { b: 5, a: 6 })后，e的值为__________，f的值为__________。](https://github.com/pwstrick/daily/issues/111)
11. [执行({ a, b=2 } = { a: 1, b: null })后，b的值为__________。](https://github.com/pwstrick/daily/issues/112)
12. [什么是模板字面量？](https://github.com/pwstrick/daily/issues/113)
13. [模板字面量有哪些局限？](https://github.com/pwstrick/daily/issues/114)
14. [ES6是否扩展了对象字面量中的属性名？](https://github.com/pwstrick/daily/issues/115)
15. [请谈谈你对Symbol的理解。](https://github.com/pwstrick/daily/issues/116)
16. [如何理解内置符号？](https://github.com/pwstrick/daily/issues/117)
17. [[...[..."..."]].length返回的结果为__________。](https://github.com/pwstrick/daily/issues/118)
18. [如何导出模块的成员？](https://github.com/pwstrick/daily/issues/119)
19. [如何导入模块的成员？](https://github.com/pwstrick/daily/issues/120)
20. [模块的默认值是指什么？](https://github.com/pwstrick/daily/issues/121)
21. [代码模块化有哪些限制？](https://github.com/pwstrick/daily/issues/122)
22. [Number.isFinite(null)返回的结果为__________。](https://github.com/pwstrick/daily/issues/123)
23. [请谈谈你对Unicode的理解。](https://github.com/pwstrick/daily/issues/124)
24. [什么叫Unicode标准化？](https://github.com/pwstrick/daily/issues/125)
25. ["My name is strick".includes("name")返回的结果为__________。](https://github.com/pwstrick/daily/issues/126)
26. [正则表达式的u标志有什么作用？](https://github.com/pwstrick/daily/issues/127)
27. [正则表达式的y标志有什么作用？](https://github.com/pwstrick/daily/issues/128)
28. [如何判断一个字符是由两个编码单元组成的？](https://github.com/pwstrick/daily/issues/129)
29. [Object.is()有什么功能？](https://github.com/pwstrick/daily/issues/130)
30. [如何使用Object.assign()？](https://github.com/pwstrick/daily/issues/131)
31. [在ES6中，自有属性的枚举顺序是怎样的？](https://github.com/pwstrick/daily/issues/132)
32. [Array.of()有什么作用？](https://github.com/pwstrick/daily/issues/133)
33. [使用fill()和copyWithin()需要的注意点有哪些？](https://github.com/pwstrick/daily/issues/134)
34. [find()和indexOf()有哪些区别？](https://github.com/pwstrick/daily/issues/135)
35. [什么是类型化数组？](https://github.com/pwstrick/daily/issues/136)
36. [类型化数组与常规数组有哪些异同？](https://github.com/pwstrick/daily/issues/137)
37. [如何使用DataView？](https://github.com/pwstrick/daily/issues/138)
38. [ES6为函数做了哪些改良？](https://github.com/pwstrick/daily/issues/139)
39. [函数的length属性有什么作用？](https://github.com/pwstrick/daily/issues/140)
40. [什么是块级函数？](https://github.com/pwstrick/daily/issues/141)
41. [new.target是由ES6引入的一个元属性，它有何用途？](https://github.com/pwstrick/daily/issues/142)
42. [箭头函数有哪些注意点？](https://github.com/pwstrick/daily/issues/143)
43. [箭头函数中的this指向哪里？](https://github.com/pwstrick/daily/issues/144)
44. [如何理解尾调用优化？](https://github.com/pwstrick/daily/issues/145)
45. [WeakSet和Set有哪些差异？](https://github.com/pwstrick/daily/issues/146)
46. [如何理解ES6新增的数据结构Map？](https://github.com/pwstrick/daily/issues/147)
47. [什么是迭代器？](https://github.com/pwstrick/daily/issues/148)
48. [什么样的对象是可迭代的？](https://github.com/pwstrick/daily/issues/149)
49. [如何使用for-of循环？](https://github.com/pwstrick/daily/issues/150)
50. [function*用来做什么？](https://github.com/pwstrick/daily/issues/151)
51. [yield关键字有什么作用？](https://github.com/pwstrick/daily/issues/152)
52. [如何通过生成器实现异步编程？](https://github.com/pwstrick/daily/issues/153)
53. [ES6的类比起用构造函数模拟的类，有哪些独有的特性？](https://github.com/pwstrick/daily/issues/154)
54. [类有哪些成员？](https://github.com/pwstrick/daily/issues/155)
55. [当super作为方法使用时，有哪些注意点？](https://github.com/pwstrick/daily/issues/156)
56. [怎么实现类的继承？](https://github.com/pwstrick/daily/issues/157)
57. [怎么理解Symbol.species？](https://github.com/pwstrick/daily/issues/158)
58. [什么是Promise？](https://github.com/pwstrick/daily/issues/159)
59. [Promise包含几种状态？](https://github.com/pwstrick/daily/issues/160)
60. [如何理解thenable？](https://github.com/pwstrick/daily/issues/161)
61. [Promise.resolve()有什么作用？](https://github.com/pwstrick/daily/issues/162)
62. [什么是代理？](https://github.com/pwstrick/daily/issues/163)
63. [什么是反射？它有什么用途？](https://github.com/pwstrick/daily/issues/164)
64. [执行[1, 2, 3, 4, 5].copyWithin(3, 2)得到的数组为__________。](https://github.com/pwstrick/daily/issues/165)
65. [如何将Map转换成数组？](https://github.com/pwstrick/daily/issues/166)
66. [yield和return有哪些区别？](https://github.com/pwstrick/daily/issues/167)

67. [下面代码的输出是什么？](https://github.com/pwstrick/daily/issues/728)
```javascript
    function sayHi() {
      console.log(name);
      console.log(age);
      var name = "Lydia";
      let age = 21;
    }
    sayHi();
```

68. [下面代码的输出是什么？](https://github.com/pwstrick/daily/issues/730)
```javascript
const shape = {
  radius: 10,
  diameter() {
    return this.radius * 2
  },
  perimeter: () => 2 * Math.PI * this.radius
}

shape.diameter()
shape.perimeter()
```

69. [哪个选项是不正确的？](https://github.com/pwstrick/daily/issues/731)
```javascript
const bird = {
  size: "small"
};
const mouse = {
  name: "Mickey",
  small: true
};
```
A: mouse.bird.size  
B: mouse[bird.size]  
C: mouse[bird["size"]]  
D: All of them are valid  

70. [下面代码的输出是什么？](https://github.com/pwstrick/daily/issues/732)
```javascript
let c = { greeting: "Hey!" };
let d;

d = c;
c.greeting = "Hello";
console.log(d.greeting);
```

71. [下面代码的输出是什么？](https://github.com/pwstrick/daily/issues/733)
```javascript
let a = 3;
let b = new Number(3);
let c = 3;

console.log(a == b);
console.log(a === b);
console.log(b === c);
```

72. [下面代码的输出是什么？](https://github.com/pwstrick/daily/issues/734)
```javascript
class Chameleon {
  static colorChange(newColor) {
    this.newColor = newColor;
  }

  constructor({ newColor = "green" } = {}) {
    this.newColor = newColor;
  }
}

const freddie = new Chameleon({ newColor: "purple" });
freddie.colorChange("orange");
```

73. [下面代码的输出是什么？](https://github.com/pwstrick/daily/issues/735)
```javascript
let greeting;
greetign = {};
console.log(greetign);
```

74. [下面代码的输出是什么？](https://github.com/pwstrick/daily/issues/736)
```javascript
function Person(firstName, lastName) {
  this.firstName = firstName;
  this.lastName = lastName;
}

const member = new Person("Lydia", "Hallie");
Person.getFullName = () => this.firstName + this.lastName;

console.log(member.getFullName());
```

75. [下面代码的输出是什么？](https://github.com/pwstrick/daily/issues/742)
```javascript
function getPersonInfo(one, two, three) {
  console.log(one);
  console.log(two);
  console.log(three);
}
const person = "Lydia";
const age = 21;
getPersonInfo`${person} is ${age} years old`;
```

76. [下面代码的输出是什么？](https://github.com/pwstrick/daily/issues/744)
```javascript
function getAge(...args) {
  console.log(typeof args);
}
getAge(21);
```

77. [下面代码的输出是什么？](https://github.com/pwstrick/daily/issues/747)
```javascript
const obj = { 1: "a", 2: "b", 3: "c" };
const set = new Set([1, 2, 3, 4, 5]);

obj.hasOwnProperty("1");
obj.hasOwnProperty(1);
set.has("1");
set.has(1);
```

78. [下面代码的输出是什么？](https://github.com/pwstrick/daily/issues/748)
```javascript
const obj = { a: "one", b: "two", a: "three" };
console.log(obj);
```

79. [下面代码的输出是什么？](https://github.com/pwstrick/daily/issues/750)
```javascript
for (let i = 1; i < 5; i++) {
  if (i === 3) continue;
  console.log(i);
}
```

80. [下面代码的输出是什么？](https://github.com/pwstrick/daily/issues/751)
```javascript
String.prototype.giveLydiaPizza = () => {
  return "Just give Lydia pizza already!";
};
const name = "Lydia";
name.giveLydiaPizza();
```

81. [下面代码的输出是什么？](https://github.com/pwstrick/daily/issues/752)
```javascript
const foo = () => console.log("First");
const bar = () => setTimeout(() => console.log("Second"));
const baz = () => console.log("Third");
bar();
foo();
baz();
```

82. [下面代码的输出是什么？](https://github.com/pwstrick/daily/issues/755)
```javascript
const person = { name: "Lydia" };
function sayHi(age) {
  console.log(`${this.name} is ${age}`);
}
sayHi.call(person, 21);
sayHi.bind(person, 21);
```

83. [下面代码的输出是什么？](https://github.com/pwstrick/daily/issues/756)
```javascript
function sayHi() {
  return (() => 0)();
}
typeof sayHi();
```

84. [下面代码的输出是什么？](https://github.com/pwstrick/daily/issues/758)
```javascript
const numbers = [1, 2, 3];
numbers[10] = 11;
console.log(numbers);
```

85. [下面代码的输出是什么？](https://github.com/pwstrick/daily/issues/759)
```javascript
(() => {
  let x, y;
  try {
    throw new Error();
  } catch (x) {
    (x = 1), (y = 2);
    console.log(x);
  }
  console.log(x);
  console.log(y);
})();
```

86. [下面代码的输出是什么？](https://github.com/pwstrick/daily/issues/760)
```javascript
[[0, 1], [2, 3]].reduce(
  (acc, cur) => {
    return acc.concat(cur);
  },
  [1, 2]
);
```

87. [如何实现Promise？](https://github.com/pwstrick/daily/issues/782)
88. [箭头函数和普通函数有什么区别？](https://github.com/pwstrick/daily/issues/805)
89. [async/await的原理是什么？](https://github.com/pwstrick/daily/issues/980)

## 思维导图
![ES6](https://github.com/pwstrick/daily/blob/master/assets/img/mind/ES6.png)

参考资料：[ES6躬行记](https://www.kancloud.cn/pwstrick/fe-questions/1094971)