How to convert string to boolean in PHP?

To convert string to boolean in PHP, the code is as follows. Use the filter_val() method−

Example

<?php
   echo "Displaying Sunday as first day of a week...
";
   $res = date('l - d/m/Y', strtotime("sunday 0 week"));
   echo "First day (next week) = ", $res."
";
   var_dump(filter_var($res, FILTER_VALIDATE_BOOLEAN));
?>

Output

This will produce the following output−

Displaying Sunday as first day of a week...
First day (next week) = Sunday - 15/12/2019
bool(false)

Example

Let us now see another example −

<?php
   var_dump(filter_var('0', FILTER_VALIDATE_BOOLEAN));
   var_dump(filter_var('1', FILTER_VALIDATE_BOOLEAN));
   var_dump(filter_var('-0', FILTER_VALIDATE_BOOLEAN));
   var_dump(filter_var('', FILTER_VALIDATE_BOOLEAN));
?>

Output

This will produce the following output−

bool(false)
bool(true)
bool(false)
bool(false)