Isset ()?

Exemples de code

7
0

isset en 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'
 */

3
0

si existent php

if (isset($var)) {
  // Code here
}
2
0

qu'est-ce qu'isset en php

The isset() function checks whether a variable is set, which means that it has to be declared and is not NULL.

This function returns true if the variable exists and is not NULL, otherwise it returns false.
0
0

js isset

if (typeof obj.foo !== 'undefined') {
  // your code here
}
0
0

isset

<?php
if (isset($_POST['name'])) $name = $_POST['name'];
else $name = '(enter your name)';
echo <<<_END
<html>
    <head>
        <title>Test</title>
    </head>
    <body>
    Your name is $name<br />
    <form method = 'post' action = 'count.php'>
        What's your name?
        <input type='text' name='name' />
        <input type='submit' />
    </form>
    </body>
</html>
_END
?>
-2
0

isset en php

//with new features in new PHP versions like 7
//you can simplify writing of isset in the following way,
//old way of isset to display name if name variable is not null
echo isset($name) ? $name : "no name"
 //new and simple way with null coalescing operator
echo $name ?? "no name"

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