php函数设定参数类型

php 函数的参数类型可以指定为类名或数组类型array，比如

这样是对的public function Right( My_Class $a, array $b )

这样是错的public function Wrong( string $a, boolean $b )

如果需要其他类型，需要在函数内部进行类型检查

参考

http://www.php.net/manual/zh/functions.arguments.php

这一段

public function Right( My_Class $a, array $b )

tells first argument have to by object of My_Class, second an array. My_Class means that you can pass also object of class that either extends My_Class or implements (if My_Class is abstract class) My_Class. If you need exactly My_Class you need to either make it final, or add some code to check what $a really.

Also note, that (unfortunately) "array" is the only built-in type you can use in signature. Any other types i.e.:

public function Wrong( string $a, boolean $b )

will cause an error, because PHP will complain that $a is not an *object* of class string (and $b is not an object of class boolean).

So if you need to know if $a is a string or $b bool, you need to write some code in your function body and i.e. throw exception if you detect type mismatch (or you can try to cast if it's doable).

function xinxi($name="",$sex="男",$age=1,$school="")

这样子的写法是正确的，

比如里边的， $school=""（表示，默认值为"")

调用的时候如下，

xinxi()//表示，参数为 $name="",$sex="男",$age=1,$school=""

xinxi(1)表示，参数为 $name="1",$sex="男",$age=1,$school=""

xinxi(1,1,1)表示，参数为 $name="1",$sex="1",$age=1,$school=""

相当于，缺少的参数，会使用对应的默认参数值

在www.php.net网站上下载一个windows版本的php压缩包，比如：php-5.6.23-win32-vc11-x86.zip，解压缩，然后找到php.ini-development，修改文件扩展名，得到php.ini，就可以进行参数配置了

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