Using WordPress ‘bool_from_yn()’ PHP function

The bool_from_yn() WordPress PHP function determines whether the input is ‘yes’ or ‘no’. It returns ‘true’ if the input is ‘y’, and ‘false’ otherwise.


This is a basic way to use the function:

$answer = bool_from_yn('y');

In this case, $answer will be true because the input is ‘y’.


  • $yn (string) – This is a required parameter. It’s a character string containing either ‘y’ (for yes) or ‘n’ (for no).

More information

See WordPress Developer Resources: bool_from_yn()


Basic Usage

In this example, we determine if the string ‘y’ is a ‘yes’.

$answer = bool_from_yn('y');
echo $answer; // Will output: 1

Evaluating ‘No’

Here, we evaluate ‘n’ as ‘no’, which will return false.

$answer = bool_from_yn('n');
echo $answer; // Will output nothing as 'false' is interpreted as empty

Input from a Form

Let’s assume we have a form where users can input ‘y’ or ‘n’. We can use our function to evaluate the user’s input.

$user_input = $_POST['user_input'];
$is_yes = bool_from_yn($user_input);

Use in Conditional Statements

We can use this function in a conditional statement to trigger different actions for ‘yes’ and ‘no’.

$answer = 'y';
if(bool_from_yn($answer)) {
  echo "You answered yes!";
} else {
  echo "You answered no!";

Validating Data

Lastly, we can use this function to validate data. If the input is not ‘y’, we assume it’s ‘no’.

$data = 'x';
$is_yes = bool_from_yn($data);
if($is_yes) {
  echo "Data is valid!";
} else {
  echo "Data is not valid!";