泛型接口的使用
代码语言：javascript复制function add<T>(arg1: T, arg2: T): T {
return arg1 arg2;
}
// <T>(arg1:T,arg2:T)=>T
add<number>(1, 2);
add<string>('1', '2')
// let addFunc: <T>(arg1: targ2: T) => T
// let addFunc: { <T>(arg1: T, arg2: T): T }
// interface GenAdder { <T>(arg1: T, arg2: T): T }
interface GenAdder<T> { (arg1: T, arg2: T): T }
let addFunc: GenAdder<string>;
addFunc = add
// addFunc<number>(1, 2)
// addFunc<string>('1', '2')
addFunc('1', '2')泛型类的使用
代码语言：javascript复制class Adder<T>{
add: (arg1: T, arg2: T) => T
}
function add(arg1, arg2) {
return arg1 arg2;
}
const adder = new Adder<number>();
adder.add = add
const stringAdder = new Adder<string>()
stringAdder.add = add
adder.add(1, 2)
stringAdder.add('1', '2')泛型约束
代码语言：javascript复制interface ILength {
length: number
}
function getLength<T extends ILength>(arg: T): T {
console.log(arg.length);
return arg;
}
getLength<string>('liuyi')
function getProperty<T, K extends keyof T>(obj: T, key: K) {
return obj[key]
}
// keyof
const people = { name: "liuyi", age: 32 }
let keys: keyof typeof people
getProperty(people, 'name')
getProperty(people, 'age')
