PHP默认参数

<?php
function sayHello($name="Ram"){
echo "Hello $name";
}
sayHello("Sonoo");
sayHello();//passing no value
sayHello("Vimal");
?>

function greeting($first="Sonoo",$last="Jaiswal"){    
   echo "Greeting: $first $last";    
}    
greeting();  
greeting("Rahul");  
greeting("Michael","Clark");  

<?php
function add($n1=10,$n2=10){
$n3=$n1+$n2;
echo "Addition is: $n3";
}
add();
add(20);
add(40,40);
?>