if(isset($_post)==true && empty($_post)==false) code example

Example 1: php isset post

if (!empty($_POST["mail"])) {
    echo "Yes, mail is set";    
} else {  
    echo "No, mail is not set";
}

Example 2: isset in php

/**
 * Returns a bool (true or false)
 */
isset($x);
/**
 * Examples
 */
$x = 'myValue';
if(isset($x)){
	echo 'x is set';
}
/**
 * this will echo out 'x is set'
 */


$x = null;
if(isset($x)){
	echo 'x is set';
}
/**
 * This will NOT echo out 'x is set'
 */


if(isset($y)){
 	echo 'y is set'; 
}
/**
 * This will NOT echo out 'y is set'
 */