swift 3 函数

收获~~~

标准的写法：

func 函数名（Argement Label Parameter Name:类型）

func testFunc(to fuck:String)->String{

    print(fuck);

    return fuck+"xxx";

}

testFunc(to: "你们")

省略Argument Label

func testFunc(_ fuck:String)->String{

    print(fuck);

    return fuck+"xxx";

}

testFunc("你们");

不写Label

func testFunc(fuck:String)->String{

    print(fuck);

    return fuck+"xxx";

}

函数命名注意：函数必须有一个动词，函数最好一个完整的句子。

The function you defined early on in this playground was called like this:

hello(name: "Maya")

But there are two problems with this function:

The function has a side effect (the name is printed to the console) but this isn’t clear from the name. A function that does work should have a verb in the name.

Functions in Swift should read as much like a sentence as possible. “Hello name Maya” is not a sentence.

To address the first problem, the function could be renamed. A better name would be printHello. But the function-as-a-sentence would still read “Print hello name Maya”, which still doesn't work. “Print hello to Maya” would be better:

func printHello(to: String) {

    print ("Hello " + to)

}

printHello(to: "Maya")