4.默认参数|可选参数

1.默认参数

var str = "hello world";
function http(method='get'){  //method 
    console.log(method);
}
http(); 
http('post')  //method='post'

function http(method:string='get'):void{
    console.log(method);
}
http();
http('post')

2.可选参数

function getInfo(name:string,age?:number):void{
  console.log(name+age);
}
getInfo('Nihao')