PHP的匿名函数

$func = function(){　　　　.... };
//把匿名函数赋值给变量，通过变量来调用

$func = function($str){ 　　 

echo $str; 
}; 

$func("hello world!");

二：闭包

将匿名函数放在普通函数中，也可以将匿名函数返回，这就构成了一个简单的闭包.

function closureFunc1(){ ???$func = function(){ ???????echo "hello"; ???}; ???$func();}closureFunc1();


//在匿名函数中引用局部变量

function closureFunc2(){ ???$num = 1; ???$func = function(){ ???????echo $num; ???}; ???$func();}closureFunc2();


上面的函数运行后，会报Notice错误，说明我们不能在匿名函数中这样使用局部变量，这时候就要引用一个php的关键字 use

function closureFunc2(){ ???$num = 1; ???$func = function() use($num){ ???????echo $num; ???}; ???$func();}closureFunc2();

// 返回匿名函数

function closureFunc3(){ ???$num = 1; ???$func = function() use($num){ ???????echo $num; ???}; ???return $func;}$func = closureFunc3(); //函数返回匿名函数$func(); //然后我们在用$func() 调用


当我们在返回匿名函数时候怎么给匿名函数传参呢？ 其实跟普通函数传参数一样

function closureFunc4(){ ???$num = 1; ???$func = function($str) use($num){ ???????echo $num; ???????echo "\n"; ???????echo $str; ???}; ???return $func;}$func = closureFunc4();$func("hello, closure4");


【怎么用闭包来改变上下文引用的变量值？】

function closureFunc5(){ ???$num = 1; ???$func = function() use($num) { ???????echo "\n"; ???????$num++; ???????echo $num; ???}; ???echo "\n"; ???echo $num; ???return $func;}$func = closureFunc5();$func();$func();$func();



【测试引用 & 符 ，再看结果】

function closureFunc5(){ ???$num = 2; ???$func = function() use(&$num) { ???????echo "\n"; ???????$num++; ???????echo $num; ???}; ???echo "\n"; ???echo $num; ???return $func;}$func = closureFunc5();$func();$func();$func();



把匿名函数当作参数传递

function callFunc($func){ ???$func("argv");}callFunc(function($str){ ???echo $str;})


更多资料请参考开发手册或者官网 ?： http://www.php.net