PHP Checking if Array is empty logic not working

Question

I have a page that loads and creates an empty array:

$_SESSION['selectedItemIDs'] = array();

If the user hasn't added any selections that get stored in the array I then check the array and branch accordingly, but there appears to be some error in my logic/syntax that is failing here.

Here's where I test if the $_SESSION['selectedItemIDs'] is set but empty:

if (isset($_SESSION['selectedItemIDs']) && $_SESSION['selectedItemIDs'] !== '') {
    // update the selections in a database
} else {
    // nothing selection so just record this in a variable
$selectedItems = 'no selected items were made';
}

When testing this with no selections if I print the $_SESSION['selectedItemIDs'] array I get this:

[selectedItemIDs] => Array
    (
    )

however the $selectedItems variable is not being set - it's evaluating the if test as true when I would expect it to be false, but I'm obviously misunderstanding something here.

You can use count function to check array length

Abhishek Sharma
– Abhishek Sharma

2016-10-26 11:54:57 +00:00
Commented Oct 26, 2016 at 11:54 — Abhishek Sharma
– Abhishek Sharma, Commented Oct 26, 2016 at 11:54
Well, array() is obviously not identical to ''…

deceze
– deceze ♦

2016-10-26 11:56:56 +00:00
Commented Oct 26, 2016 at 11:56 — deceze
– deceze ♦, Commented Oct 26, 2016 at 11:56

RJParikh · Accepted Answer · 2016-10-26 11:59:12Z

7

Use empty() function.

empty() - it will return true if the variable is an empty string, false, array(), NULL, “0?, 0, and an unset variable.

Syntax

empty(var_name)

Return value

FALSE if var_name has a non-empty and non-zero value.

Value Type :

Boolean

List of empty things :

"0" (0 as a string)
0 (0 as an integer)
"" (an empty string)
NULL
FALSE
"" (an empty string)
array() (an empty array)
$var_name; (a variable declared but without a value in a class)

Code

if (!empty($_SESSION['selectedItemIDs']) ) {
    // update the selections in a database
} else {
    // nothing selection so just record this in a variable
$selectedItems = 'no selected items were made';
}

edited Oct 26, 2016 at 11:59

answered Oct 26, 2016 at 11:54

RJParikh

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Comments

Karol Gasienica · Accepted Answer · 2016-10-26 12:01:29Z

0

$_SESSION['selectedItemIDs'] = array();

this variable is already set, but is empty. isset($_SESSION['selectedItemIDs']) check if variable exists, even if it's nothing in.

To check if there is anything just use

empty($_SESSION['selectedItemIDs']);

PHP DOC - empty

edited Oct 26, 2016 at 12:01

answered Oct 26, 2016 at 11:55

Karol Gasienica

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Comments

Jay Blanchard · Accepted Answer · 2016-10-26 12:04:14Z

0

if (!empty($_SESSION['selectedItemIDs'])) {
    // update the selections in a database
} else {
    // nothing selection so just record this in a variable
    $selectedItems = 'no selected items were made';
}

isset($_SESSION['selectedItemIDs']) => it will check is this parameter is set or not which is correct.

$_SESSION['selectedItemIDs'] !== '' => this will exactly compare that your parameter type is not '' but here i guess your selectedItemIDs is array so it let you go inside

edited Oct 26, 2016 at 12:04

Jay Blanchard

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answered Oct 26, 2016 at 11:57

Binit Ghetiya

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4 Comments

Jay Blanchard Over a year ago

Why should the OP "try this"? A good answer will always have an explanation of what was done and why it was done in such a manner, not only for the OP but for future visitors to SO.

Binit Ghetiya Over a year ago

isset($_SESSION['selectedItemIDs']) && $_SESSION['selectedItemIDs'] !== ''

Jay Blanchard Over a year ago

You need to add an explanation to your answer, not in comments.

Binit Ghetiya Over a year ago

isset($_SESSION['selectedItemIDs']) => it will check is this parameter is set or not which is correct. $_SESSION['selectedItemIDs'] !== '' => this will exectly compare that your parameter type is not '' but here i guess your selectedItemIDs is array so it let you go inside Thanks

Abdullah A Malik · Accepted Answer · 2016-10-26 12:02:32Z

-1

You can check the count of this array.

if (isset($_SESSION['selectedItemIDs']) && count($_SESSION['selectedItemIDs']) > 0) {
    // update the selections in a database
} else {
    // nothing selection so just record this in a variable
$selectedItems = 'no selected items were made';
}

answered Oct 26, 2016 at 12:02

Abdullah A Malik

3542 gold badges4 silver badges12 bronze badges

1 Comment

mickmackusa Over a year ago

empty() does the same thing.

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