数组、元组、枚举

数组

let a: number[] = [1, 2, 'abc'];//错误
let a: (number|string)[] = [1, 2, 'abc'];//正确
a.push(true);//错误

元组

let a:[number, boolean] = [12, true];
a.push(33);//成功，只管前两种
console.log(a);//[ 12, true, 33 ]

枚举

enum Color {Red, Green, Blue};
let c: Color = Color.Blue;
console.log(c);//2