增删改查
let arr = []
let obj = {}
let map = new Map()
let set = new Set()
let item = {fruit:'apple'}
// 添加
arr.push(item)
obj['fruit']=item.fruit
map.set('fruit','apple')
set.add(item)
console.log('add',arr,obj,map,set);
// 查询
let reArr = arr.includes(item)
let reObj = 'fruit' in obj
let reMap = map.has('fruit')
let reSet = set.has(item)
console.log('search',reArr,reObj,reMap,reSet);
// 修改
arr.forEach(item=>{
item.fruit = item.fruit?'orange':''
})
obj['fruit'] = 'orange'
map.set('fruit','orange')
set.forEach(item=>{item.fruit = item.fruit?'orange':''})
console.log('update',arr,obj,map,set);
// 删除
let index = arr.findIndex(item=>{
return item.fruit
})
arr.splice(index,1)
delete obj.fruit
map.delete('fruit')
set.delete(item)
console.log('delete',arr,obj,map,set);
类型转换
// 类型转换
// Object 与 Map 转换
let obj = {
name:'xiaoming',
age:19
}
let map = new Map(Object.entries(obj))//接收键值对
let obj2 = Object.fromEntries(map)
console.log('map',map,'obj',obj2);
// Array 与 Set 转换
let arr = [1,1,2,2,3,3,4]
let set = new Set(arr)
let arr2 = Array.from(set)
console.log('arr',arr2,'set',set);