The ctype_alpha method can be used to check if all the characters of the text are alphabetical.
The alphabet characters include both upper case
A-Zand lower casea-zcharacters.
ctype_alpha(mixed $text): bool
This method returns a Boolean value.
<?php$str = "abcABC";printIsAlpha($str);$str = "123ABccAAA";printIsAlpha($str);$str = "A B";printIsAlpha($str);function printIsAlpha($str){echo "The string is: ". $str. "\n";echo "Is Alpha: ";var_dump(ctype_alpha($str));echo "---------\n";}?>
In the code above:
We used the ctype_alpha method to check if the string contains only alphabetical characters.
For the abc string, the ctype_alpha returns true.
But for the 123ABccAAA string, the ctype_alpha method returns false, because the string contains numeric characters.
Similarly, for A B, the ctype_alpha method returns false because the non-alphabetical character space is present in the string.
If an int value from -128 to 128 is passed as an argument, then it is internally converted as an ASCII character and checked to see if the converted character is an alphabet. For example:
<?phpvar_dump(ctype_alpha(97));?>
In the code above, we passed 97 as an argument. It is internally converted as ASCII character a and checked to see if it is an alphabet. a is a valid alphabet, so true is returned.