TypeScript 四、函數

無參數無返回值

let names : string[] = ["張三","李四","王五"];
function func()
{	
	for(let i = 0; i < 3; i++)
	{
		console.log(names[i]);
	}
}
或者
let func = function ()
{	
	for(let i = 0; i < 3; i++)
	{
		console.log(names[i]);
	}
}
或者
let func = () =>
{	
	for(let i = 0; i < 3; i++)
	{
		console.log(names[i]);
	}
}

func();
--->
張三
李四
王五

有參數無返回值

let names : string[] = ["張三","李四","王五"];
function func(char:string)
{	
	for(let i = 0; i < 3; i++)
	{
		if(char == names[i])
		{
			console.log(i);
		}
	}
}

func("李四");
--->
1

let names : string[] = ["張三","李四","王五"];
function func(char:string, num:number)
{	
	for(let i = 0; i < 3; i++)
	{
		if(char == names[i] && i == num)
		{
			console.log("OK");
		}
	}
}

func("李四",1);
--->
OK

無參數有返回值

let names : string[] = ["張三","李四","王五"];
function func()
{	
	for(let i = 0; i < 3; i++)
	{
		if(names[i] == "李四")
		{
			return false;
		}
	}
}

let bo = func();
console.log(bo);

--->
false

 有參數有返回值

let names : string[] = ["張三","李四","王五"];
function func(char:string, num:number)
{	
	for(let i = 0; i < 3; i++)
	{
		if(char == names[i] && i == num)
		{
			return true;
		}
	}
}

let bo = func("李四",1);
console.log(bo);

--->
true

let names : string[] = ["張三","李四","王五"];
function func(char:string, num:number):boolean//無返回值時可寫爲void
{	
	for(let i = 0; i < 3; i++)
	{
		if(char == names[i] && i == num)
		{
			return true;//無返回值時可只寫return表示跳出/結束函數
		}
	}
}

let bo = func("李四",1);
console.log(bo);
--->
true