<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
</head>
<body>
<script>
//输入【1,2,3,1】 输出true
//输入【1,2,3,4】 输出false
let len=0;
const containsDuplicate=function(nums){
let map=new Map();
for(let i of nums){
if(map.has(i)){
return true;
}else{
map.set(i,1);
}
}
return false;
}
var um=containsDuplicate([1,2,3,5,1]);
console.log(um);
</script>
</body>
</html>