PHP实现函数重载

本来php?name=PHP">PHP是不支持函数重载的!

php 作为一种弱类型语言，本身不能像强类型如java ，c++那样，直接的实现重载。不过可以通过一些方法，间接的实现重载。

1.可以使用func_get_args()和func_num_args()这两个函数实现函数的重载!!

PHP代码：

    <span>function</span><span> rewrite() {   
            </span><span>$args</span> = <span>func_get_args</span><span>();   
            </span><span>if</span>(<span>func_num_args</span>() == 1<span>) {   
                    func1(</span><span>$args</span>[0<span>]);   
            } </span><span>else</span> <span>if</span>(<span>func_num_args</span>() == 2<span>) {   
                    func2(</span><span>$args</span>[0], <span>$args</span>[1<span>]);   
            }   
    }   
      
    </span><span>function</span> func1(<span>$arg</span><span>) {   
            </span><span>echo</span> <span>$arg</span><span>;   
    }   
      
    </span><span>function</span> func2(<span>$arg1</span>, <span>$arg2</span><span>) {   
            </span><span>echo</span> <span>$arg1</span>, ' ', <span>$arg2</span><span>;   
    }   
      
    rewrite(</span>'PHP'); <span>//</span><span>调用func1   </span>
    rewrite('PHP','China'); <span>//</span><span>调用func2   </span>

2.使用默认值，从而根据输入，得到自己想要的结果：

 <span>function</span> test(<span>$name</span>="小李",<span>$age</span>="23"<span>){  
        </span><span>echo</span> <span>$name</span>."  ".<span>$age</span><span>;  
        }  
  
    test();  
    </span><span>echo</span> "<br/>"<span>;  
    test(</span>"a"<span>);  
    </span><span>echo</span> "<br/>"<span>;  
    test(</span>"a","b");