What is PHP is_bool() Function?
If you want to know whether a variable’s type is exactly boolean type or not, use is_bool() function. there are only two Boolean values – TRUE and FALSE.
Syntax:
is_bool(variable)
Parameters:
The Function has 1 parameter which is required-
variable (Required): It specifies a variable.
Return Values:
The function returns-
- TRUE, if the variable is a boolean type variable
- FALSE, if the variable is not a boolean type variable
Examples:
Example 1:
<?php
if (is_bool(TRUE) === TRUE) {
echo "Yes, this is a boolean.";
}else {
echo "No, this is not a boolean.";
}
?>
Output:
Yes, this is a boolean.
Example 2:
<?php
if (is_bool(1) === TRUE) {
echo "Yes, this is a boolean.";
}else {
echo "No, this is not a boolean.";
}
?>
Output:
No, this is not a boolean.
Example 3:
<?php
if (is_bool("TRUE") === TRUE) {
echo "Yes, this is a boolean.";
}else {
echo "No, this is not a boolean.";
}
?>
Output:
No, this is not a boolean.
Notes on is_bool() Function:
- The is_bool() function doesn’t consider “falsy” and “truthy” values as Boolean values. “Truthy” / “FALSY” values are those that are not strictly the boolean but are treated so. Truthy example: 1, “1”, “true”etc. Falsy example: 0, “FALSE” etc.
PHP Version Support:
PHP 4, PHP 5, PHP 7, PHP 8
Summary: PHP is_bool() Function
is_bool() is a built-in variable handling function. to know exactly whether a variable is booleaan or not, use this function.