checking for null and assigning in php

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Where can I read about conditionals done with ? and :

I want do the following without using if else or a ternary operator:

if $_GET['a'] is not null then set $a= $_GET['a'] else set its value to "default".

I tried $a= $_GET['a'] || "default". but it doesnt work. I remember seeing something like this in a code sample, but I can't recall now.

A simple Google search will give u http://php.net/manual/en/function.is-null.php — Prashant Singh, Oct 22 '12 at 07:09
Then just use an *if* or actually understand the operators. They are documented. `(NULL !== $a = $_GET['a']) || $a = "default";`. This is trivial material. — hakre, Oct 22 '12 at 07:14
Although I am not too sure I understand what the OP is trying to achieve, I'm pretty sure he DIDN'T ask "how to determine if a variable contains null" and cleraly stated that he DIDN't want to use the ternary operator... — Pierre Henry, Oct 22 '12 at 07:15
Starting with PHP 5.3, a shorter version of the ternary operator is available, so you could write: `$a= @$_GET['a'] ?: "default";` - which is almost equivalent to `a = something || 'default';` in javascript (except that it may raise an E_NOTICE error, therefore i added an `@`). Starting with PHP7 you can use the fully equivalent null coalesce operator: `$a= $_GET['a'] ?? "default";` — Philzen, Jan 19 '17 at 16:41

score 2 · Accepted Answer · edited Jan 19 '17 at 15:11

2

I think a ternary if is your best bet here.

In this case I would use isset check - to determine if the key is set and is not null:

$a = isset($_GET['a']) ? $_GET['a'] : "default"

The or operator || doesn't work to null coalesce like that in PHP, but you might have seen it in JavaScript where it can be used to set a value to the first non-false result:

e.g

var a = get['a'] || 'default';

edited Jan 19 '17 at 15:11

Philzen

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answered Oct 22 '12 at 07:17

benedict_w

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score 0 · Answer 2 · answered Oct 22 '12 at 07:14

0

Refer this PHP shorthand if/else (ternary) information in http://davidwalsh.name/php-ternary-examples

and also

http://davidwalsh.name/learning-ternary-operators-tips-tricks

answered Oct 22 '12 at 07:14

Prasath Albert

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Not just link. They disappear over time. Add the code-examples. Otherwise just leave a comment with the links. – hakre Oct 22 '12 at 07:17

score 0 · Answer 3 · answered Oct 22 '12 at 07:26

Well, people here doesn't seem to bother reading the entire question this late.

That sintax you wrote works on some other languages but apparently not on php. I think you should just stick to the ternary operator or write a function for that as a shortcut if you're going to use this kind of verification a lot on your page.

function GET($v, $default)
{
    return !isset($_GET[$v]) || empty($_GET[$v]) ? $default : $_GET[$v];
}

$a = GET("a", "default");

checking for null and assigning in php

3 Answers3