本文实例讲述了PHP利用func_get_args和func_num_args函数实现函数重载的方法。分享给大家供大家参考。具体方法分析如下:
学习php的朋友都知道php本身是没有函数重载这一说的,更没说像java,c那样使用方法,但如果我们深入了解一下会发现可以在php中使用func_get_args()和func_num_args()函数实现函数重载,下面来举两个函数重载例子.这两个函数实现函数的重载.
1、默认参数,如果一个函数里面,这不是必须参数,而添加相应的默认值,就可以完成相应的功能,代码如下:
代码如下:
function overloadFun($param1, $param2 = '1',$param3 = true)
{
// do something
}
利用函数func_get_args()和call_user_func_array(),PHP代码如下:
代码如下:
function rewrite() {
$args = func_get_args();
if(func_num_args() == 1) {
func1($args[0]);
} else if(func_num_args() == 2) {
func2($args[0], $args[1]);
}
}
function func1($arg) {
echo $arg;
}
function func2($arg1, $arg2) {
echo $arg1, ' ', $arg2;
}
rewrite('PHP'); //调用func1
rewrite('PHP','China'); //调用func2
2、使用默认值,从而根据输入,得到自己想要的结果,代码如下:
代码如下:
function test($name="小李",$age="23"){
echo $name." ".$age;
}
test();
echo "
";
test("a");
echo "
";
test("a","b");
3、利用__call($name, $arg) 函数进行处理,代码如下:
代码如下:
class OverLoad{
function __call($name, $args)
{
if($name=='overloadFun')
{
switch(count($args))
{
case 0: $this->overloadFun0();break;
case 1: $this->overloadFun1($args[0]); break;
case 2: $this->overloadFun2($args[0], $args[1]); break;
default: //do something
break;
}
}
}
function overloadFun0()
{
echo 0;
}
function overloadFun1($var1)
{
echo $var1;
}
function overloadFun2($var1,$var2)
{
echo $var1+$var2;
}
}
$test=new OverLoad();
$test->overloadFun()."
".
$test->overloadFun(1)."
".
$test->overloadFun(1,2)."
";
?>
有了这样的方法之后我们就可以利用它们来实现简单函数重载了,但有一点要注明的是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,至少现在不可以以后版本会不会有我们不知道.
希望本文所述对大家的PHP程序设计有所帮助。

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