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| // 函数定义
function add1(x:number, y:number){
return x + y;
}
let add2: (x:number, y:number) => number
type add3 = (x:number, y:number) => number
interface add4{
(x:number,y:number): number;
}
// add1(1,2,3)
function add5(x:number,y?:number){
return y?x+y:x;
}
add5(1)
function add6(x:number,y=0,z:number,q=1){
return x + y + z + q;
}
console.log(add6(1,undefined, 3));
function add7(x:number,...rest:number[]){
return x + rest.reduce((pre, cur)=> pre +cur) ;
}
console.log(add7(1,2,3,4,5))
function add8(...rest: number[]): number;
function add8(...rest: string[]): string;
function add8(...rest: any[]): any{
let first = rest[0];
if(typeof first === 'string'){
return rest.join('')
}
if(typeof first === 'number'){
return rest.reduce((pre, cur)=> pre + cur);
}
}
console.log(add8(1,2,3));
console.log(add8('a','b','c'));
|