php匿名函数与闭包的简单使用

1、匿名函数的概念：是指没有函数名的方法

      $func = function($param){

         echo $param;

      }

2、闭包是值将匿名函数当作参数传入，也可以返回

      a：function a(){

                  $test = function('param'){

                        echo 'param';

                  }

                 $test('test');

            }

           a();//输出test

        b：function a(){

                    $test = function('param'){

                           echo 'param';

                     }

                     return $test;

               }

              $test = a();

               $test('test');//将匿名函数返回

         c：function a($test){

                      $test('test');

               }

             $test = function('test'){

                       echo 'test';

             }

            a($test);

3、闭包函数引用外部变量需要使用use关键字

     function a(){

             $param1 = 'yes';

             $param2 = 'no';

             $test = function() use ($param1){

                  echo $param1.'\r\n';

                  echo $param2.'\r\n';//这里会报错

             }

     }