看下面的面试题

我们不能自定义数组里面的key
map数据结构就解决了这一问题，map可以自定义数组的key

set

javascript"><script>
const m=new Map([
    ["name","aa"],
    ["age",'18'],
    ["name:a","age:b"]
])
m.set([function(){return "12"}],[function(){return "15"}])
console.log(m.get("age"));
console.log(m);
</script>

get

javascript"><script>
const m=new Map([
    ["name","aa"],
    ["age",'18'],
    ["name:a","age:b"]
])
console.log(m.get("age"));
console.log(m);
</script>

delete

javascript"><script>
const m=new Map([
    ["name","aa"],
    ["age",'18'],
    ["name:a","age:b"]
])
m.delete('age')
console.log(m);
</script>

clear

javascript"><script>
const m=new Map([
    ["name","aa"],
    ["age",'18'],
    ["name:a","age:b"]
])
m.clear()
console.log(m);
</script>

forEach

javascript"><script>
const m=new Map([
    ["name","aa"],
    ["age",'18'],
    ["name:a","age:b"]
])
m.forEach(function(value,key,map){
    console.log(value+'-----'+key+'-----'+map);
})
console.log(m);
</script>

for of

javascript"><script>
const m=new Map([
    ["name","aa"],
    ["age",'18'],
    ["name:a","age:b"]
])
for(key of m){
    console.log(key);
}
console.log(m);
</script>

has

javascript"><script>
const m=new Map([
    ["name","aa"],
    ["age",'18'],
    ["name:a","age:b"]
])
console.log(m.has("age"));
console.log(m.has("a"));
console.log(m);
</script>

size

javascript"><script>
const m=new Map([
    ["name","aa"],
    ["age",'18'],
    ["name:a","age:b"]
])
console.log(m.size);
console.log(m.length);
</script>