Why is it recommended to use preg functions or string functions like strpos instead of eregi() for simple tasks like checking for spaces in a string?

Using eregi() for simple tasks like checking for spaces in a string is not recommended because it is a case-insensitive function and has been deprecated in PHP 5.3. Instead, it is better to use preg functions or string functions like strpos, which are more efficient and provide better performance.

// Using strpos to check for spaces in a string
$string = "Hello World";
if(strpos($string, ' ') !== false){
    echo "String contains a space";
} else {
    echo "String does not contain a space";
}