PHP | is_double() Function

<?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' 

?> 

<?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"; 
?>