基础类型
布尔值
let isDone: boolean = false;
数字
let decLiteral: number = 6;
let hexLiteral: number = 0xf00d;
let binaryLiteral: number = 0b1010;
let octalLiteral: number = 0o744;
字符串
let aname: string = 'bob';
let age: number = 18;
let sentence: string = `My name is ${ name }.
I am be ${ age } years old.`;
数组
let list: number[] = [1, 2, 3, 4];
let arr: Array<number> = [1, 2, 3, 4];
元组Tuple
let tupel: [string, number] = ['hello', 20, 20, 'false'];
tupel[0] = 'hi';
枚举
enum Color {Red, Green = 3, Blue};
let color: Color = Color.Blue;
Any
let notSure: any = 4;
notSure.toFixed();
notSure = false;
let notSureList: any[] = [1, true, 'free'];
notSureList[1] = 100;
Void
function warnInfo (argument): void {
alert("This is my warning message");
}
let unusable: void = undefined;
Null 和 Undefined
let isNull: null = null;
let isUndefined: undefined = undefined;
Never
function error (message: string): never {
throw new Error(message);
}
断言
let someValue: any = 'this is a string';
let strLength1: number = (<string>someValue).length;
let strLength2: number = (someValue as string).length;