map:映射 1对1

let arr=[100, 98, 37, 28, 19, 96, 56, 67];
let res=arr.map(item=>item>=60);
console.log(arr, res);

[100, 98, 37, 28, 19, 96, 56, 67]
[true,true,false,false,false,true,false,true]