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Regarding if statements in PHP

this is a simple question. But Here I need to know how if condition work with only one variable.

$category='';

if ($category) {

}

can you tell what actually check in If condition? Condition has only one variable..

is it checking variable is TRUE or FALSE?

Answer 1

PHP is a weak typed language. To understand what is evaluated in the if condition, see the conversion rules for booleans.

Quoting from the manual:

When converting to boolean, the following values are considered FALSE:

• the boolean FALSE itself
• the integer 0 (zero)
• the float 0.0 (zero)
• the empty string, and the string "0"
• an array with zero elements
• an object with zero member variables (PHP 4 only)
• the special type NULL (including unset variables)
• SimpleXML objects created from empty tags

Therefore, your condition will be evaluated as FALSE, since $category == '' and (bool) '' === FALSE