Multi tool use

How to check if “ ” exist?

When I print a variable, I get a blank result and when I inspect the element I see that  .

 

I tried to check if the variables is empty or equals this value:

ir( empty($string) || $string == " " || strpos($string, " ") || $string == " "){
//Do Something.
}


But the code inside that condition is not executed.

When I var_dump($string), I get:

var_dump($string)

string(2) " "


What should I do to check if the variable equals or contain that?

(!isset($string) || trim($string) === '')

ir

if

2 Answers
2

First of all, People get tripped up on this move all the time...

strpos($string, " ")


If   is at the start of your string, then the evaluated result is 0 ("offset position") AND 0 is loosely compared to false in the way that you have crafted your conditional expression.

 

0

0

false

You need to explicitly check for false (strict check) from strpos() like this:

false

strpos()

if (empty($string) || strpos($string, " ") !== false || $string == " ") {
//Do Something.
}


You have a multibyte space evidenced by when you "highlight" the character with your cursor -- it only has a character length of one, but when you call var_dump() there is a byte count of 2.

var_dump()

2

trim() can't help you. ctype_space() can't help you. You need something that is multibyte aware.

trim()

ctype_space()

To allow the most inclusive match, I'll employ a regular expression that will search for all whitespace characters, invisible control characters, and unused code points.

if (empty($string) || preg_match("/^[pZpC]+$/u", $string)) {


This will check if the string is truly empty or is entirely composed of one or more of the aforementioned characters.

Here's a little demo: https://3v4l.org/u7eoK

(I don't really think this is a   issue, so I am leaving that out of my solution.)

 

Scroll down this resource: https://www.regular-expressions.info/unicode.html

The solution, If the utf-8 is used:

$a = str_replace("xC2xA0", '', $a);


If ASCII :

$a = str_replace("xA0", '', $a);


Then the $a is empty now and you could check it using if(empty($a))

if(empty($a))

The answer exists here: Does html_entity_decode replaces   also? If not how to replace it?

empty()

isset()

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