PHP | is_double() Function

The is_double() function is an inbuilt function in PHP which is used to find whether the given value is a double or not.

Syntax:

bool is_double( $variable_name )

Parameters: This function accepts one parameter as mentioned above and described below:

• $variable_name: This parameter holds the value which need to check.

Return Value: It is a boolean value i.e. either TRUE if $variable_name contains is a double value, otherwise returns FALSE.

Below programs illustrate the is_double() function in PHP:

Program 1:

<?php
// PHP code to implement is_double()
// function

function square($num)
{
    return (is_double($num));
}

echo square(9.09) ."\n"; // outputs '1'.
echo square(FALSE) ."\n"; // gives no output.
echo square(14) ."\n"; // gives no output.
echo square(56.30) ."\n"; // outputs '1'

?>

Output:

1


1

Program 2:

<?php
// PHP code to implement is_double()
// function

$variable_name1 = 67.099;
$variable_name2 = 32;
$variable_name3 = "abc";
$variable_name4 = FALSE;

// $variable_name1 is double value, gives TRUE
if (is_double($variable_name1))
    echo "$variable_name1 is a double value. \n";
else
    echo "$variable_name1 is not a double value. \n";

// $variable_name2 is not a double value, gives FALSE
if (is_double($variable_name2))
    echo "$variable_name2 is a double value. \n";
else
    echo "$variable_name2 is not a double value. \n";

// $variable_name3 is not a double value, gives FALSE
if (is_double($variable_name3))
    echo "$variable_name3 is a double value. \n";
else
    echo "$variable_name3 is not a double value. \n";

// $variable_name4 is not a double value, gives FALSE
if (is_double($variable_name4))
    echo "FALSE is a double value. \n";
else
    echo "FALSE is not a double value. \n";
?>

Output:

67.099 is a double value. 
32 is not a double value. 
abc is not a double value. 
FALSE is not a double value.

Reference: https://www.php.net/manual/en/function.is-double.php