基础定义
function call(name:string):void{
console.log(name)
}
const call = (name:string):void{ console.log(name) }
可选参数
function joinName(firstName: string, lastName?:string):string {
return `${ firstName }${ lastName ? ' ' + lastName : '' }`
}
默认参数
- 所有默认参数都是可选的
- 非必须在必选参数后
- 可通过显示设置 undefined 获取默认值
function add1(a:number, b:number = 1):number{
return a + b
}
add(10)
add(10, undefined)
剩余参数
function print(...info:string[]){
console.log(...info)
}
重载
function pack(info:number):number[]
function pack(info:string):string
function pack(info):any{
if(typeof info === string){
return info
}
if(typeof info === number){
return [info]
}
}