set和map ​

let m = setInterval(() => console.log('Hi'), 1000)
console.log(m)

let m = setInterval(() => console.log('Hi'), 1000)
console.log(m)

for (const [i, v] of [`a`, `b`, `c`].entries()) {
  console.log(i, v)
}
// 例子 6-2
const arr = [
  [234, 5],
  [6, 78],
  [4, 5],
]
const map = new Map(arr)

// 遍历 key 值
for (const key of map.keys()) {
  console.log(key)
}

// 遍历 value 值
for (const value of map.values()) {
  console.log(value)
}

// 遍历 key 和 value 值(一)
for (const item of map.entries()) {
  console.log(item[0], item[1])
}
const data = new Map(arr)
// 遍历 key 和 value 值(二)
for (const [key, value] of data) {
  console.log(key)
}
export {}

for (const [i, v] of [`a`, `b`, `c`].entries()) {
  console.log(i, v)
}
// 例子 6-2
const arr = [
  [234, 5],
  [6, 78],
  [4, 5],
]
const map = new Map(arr)

// 遍历 key 值
for (const key of map.keys()) {
  console.log(key)
}

// 遍历 value 值
for (const value of map.values()) {
  console.log(value)
}

// 遍历 key 和 value 值(一)
for (const item of map.entries()) {
  console.log(item[0], item[1])
}
const data = new Map(arr)
// 遍历 key 和 value 值(二)
for (const [key, value] of data) {
  console.log(key)
}
export {}

// 例子 5-2
// 根据颜色找出对应的水果

// Bad
function test1(color) {
  switch (color) {
    case `red`:
      return [`apple`, `strawberry`]
    case `yellow`:
      return [`banana`, `pineapple`]
    case `purple`:
      return [`grape`, `plum`]
    default:
      return []
  }
}

test1(`yellow`) // ['banana', 'pineapple']
// Good
const fruitColor1 = {
  red: [`apple`, `strawberry`],
  yellow: [`banana`, `pineapple`],
  purple: [`grape`, `plum`],
}

function test2(color) {
  return fruitColor1[color] || []
}
// Better
const fruitColor2 = new Map()
  .set(`red`, [`apple`, `strawberry`])
  .set(`yellow`, [`banana`, `pineapple`])
  .set(`purple`, [`grape`, `plum`])

function test3(color) {
  return fruitColor2.get(color) || []
}
export {}

// 例子 5-2
// 根据颜色找出对应的水果

// Bad
function test1(color) {
  switch (color) {
    case `red`:
      return [`apple`, `strawberry`]
    case `yellow`:
      return [`banana`, `pineapple`]
    case `purple`:
      return [`grape`, `plum`]
    default:
      return []
  }
}

test1(`yellow`) // ['banana', 'pineapple']
// Good
const fruitColor1 = {
  red: [`apple`, `strawberry`],
  yellow: [`banana`, `pineapple`],
  purple: [`grape`, `plum`],
}

function test2(color) {
  return fruitColor1[color] || []
}
// Better
const fruitColor2 = new Map()
  .set(`red`, [`apple`, `strawberry`])
  .set(`yellow`, [`banana`, `pineapple`])
  .set(`purple`, [`grape`, `plum`])

function test3(color) {
  return fruitColor2.get(color) || []
}
export {}

const s = new Set()
;[1, 2, 34, 5].forEach((x) => {
  s.add(x)
})
for (const i of s) {
  const m = 343
  console.log(m)
  console.log(i)
}
console.log([...new Set(`aaadddbdde`)].join(``)) //去除重复字符
const prop = new Set()
prop.add(`hello`)
prop.add(`lisck`)
if (prop.has(`hello`)) {
  console.log(`Hello`)
}
const y = new Set([`red`, `green`, `blue`])

for (const string of y) {
  console.log(string)
}
const foos = new WeekSet()
class Foo {
  constructor() {
    foos.add(this)
  }
  method() {
    if (!foos.has(this)) {
      console.log(`helo`)
    }
  }
}

const s = new Set()
;[1, 2, 34, 5].forEach((x) => {
  s.add(x)
})
for (const i of s) {
  const m = 343
  console.log(m)
  console.log(i)
}
console.log([...new Set(`aaadddbdde`)].join(``)) //去除重复字符
const prop = new Set()
prop.add(`hello`)
prop.add(`lisck`)
if (prop.has(`hello`)) {
  console.log(`Hello`)
}
const y = new Set([`red`, `green`, `blue`])

for (const string of y) {
  console.log(string)
}
const foos = new WeekSet()
class Foo {
  constructor() {
    foos.add(this)
  }
  method() {
    if (!foos.has(this)) {
      console.log(`helo`)
    }
  }
}