泛型的使用

//-------------------泛型方法--------------------
function getData1(value: string): string {return value;
}function getData2(value: number): number {return value;
}//any 放弃了类型检查，传入的参数类型和返回参数类型不一致
function getData3(value: any): any {return value;
}// T表示泛型：具体什么类型是调用这个方法的时候决定的
//泛型函数
function getData<T>(value: T): T {return value;
}var p1 = getData<number>(123);var p2 = getData<string>('123');
//-------------------------------普通类--------------------------
class MinClass {public list: number[] = [];add(num: number) {this.list.push(num)}min(): number {// var minNum = Math.min(...this.list)//因为要比较数字 和 字符串，所以用下面的方法var minNum = this.list[0];for (var i = 0; i < this.list.length; i++) {if (minNum > this.list[i]) {minNum = this.list[i];}}return minNum;}
}var m = new MinClass();
m.add(20);
m.add(30);
m.add(10);
alert(m.min())//----------------------------泛型类------------------------namespace HX2 {class MinClass<T>{public list: T[] = [];add(num: T) {this.list.push(num)}min(): T {// var minNum = Math.min(...this.list)//因为要比较数字 和 字符串，所以用下面的方法var minNum = this.list[0];for (var i = 0; i < this.list.length; i++) {if (minNum > this.list[i]) {minNum = this.list[i];}}return minNum;}}//实例化 指定类的T 代表的类型是 numbervar m = new MinClass<number>();m.add(20);m.add(30);m.add(10);alert(m.min())//实例化 指定类的T 代表的类型是 stringvar m2 = new MinClass<string>();m2.add('b');m2.add('a');m2.add('m');alert(m2.min())}
//---------------------泛型的使用方式--------------------------
//函数声明
function fun5<A>(name: A): A {return name
}//函数表达式
var fun2 = function <T>(name: T): T {return name;
}//匿名泛型
var fun3 = <T>(name: T) => name;
//----------------------------------泛型接口--------------------------------
//定义泛型接口
interface ConfigFn<T> {(value1: T): T;
}var setData: ConfigFn<string> = function <T>(value1: T): T {return value1
}
var s1 = setData('张三');
console.log(s1);//   number
var setData2: ConfigFn<number> = function <T>(value1: T): T {return value1
}
var s2 = setData2(12);
console.log(s2);
interface Search {<T>(a: T, b: T): boolean
}
//泛型函数
let f4: Search = function <T>(a: T, b: T): boolean {return a == b
}var re = f4<number>(123, 123);console.log(re)var re2 = f4<string>('123', '123');
console.log(re2)