Question

I got a question when I was doing some Array in PHP.
I don’t know how to write the code for the following case:

$arrs = array("a@c", "cr", "exd", "hello", "gg%j", "hwa", "@", "8");

foreach ($arrs as $arr){
// if $arr does not belong to any characters from a to z, 
// then there must be some special character in it.
// Say for example, "a@c" will still be regarded as fine string, 
// since it contains normal characters a and c.
// another example, "gg%j" will also be fine, since it contains g and j.
}

Answer 1

You could use a regex, and the [preg_match][1] function :

$arrs = array("abc", "cr", "exd", "hello", "gj", "hwa", "@", "8");
foreach ($arrs as $arr){
    // if $arr does not belong to any characters from a to z, 
    // then there must be some special character in it.
    if (!preg_match('/^[a-z]*$/', $arr)) {
        var_dump($arr);
    }
}

Which would get you the following output :

string '@' (length=1)
string '8' (length=1)

Here, the regex is matching :

• beginning of string : ^
• any number of characters between a and z : [a-z]*
• end of string : $

So, if the string contains anything that’s not between a and z, it will not match ; and var_dump the string.
[1]: https://www.php.net/preg_match