php isset — 检测变量是否设置

Posted 2020-06-27 MAKE-IN-中国

例子

$a = 336 ;
$b = 33 ;
function large($x,$y){
    if((!isset($x))||(!isset($y))){
       // echo "this function require two numbers";
      return false;
    }
    if($x>$y){
        return $x;
    }else{
        return $y;
    }
}
echo large($v,$b);