How to check if the string has alphabets in PHP
The ctype_alpha and ctype_digit doesn't help in it. is their any method?
asked Mar 17, 2014 at 15:17
7
You can use preg_match for this.
if[preg_match["/[a-z]/i", $string]]{
print "it has alphabet!";
}
If you want to check for all the characters to be alphabet, then use anchor around the regex. For example ^[a-z]+$.
answered Mar 17, 2014 at 15:18
Sabuj HassanSabuj Hassan
37.2k12 gold badges73 silver badges84 bronze badges
Posted as requested
/^[a-zA-Z]+$/ alpha, /^[0-9]+$/ num, /^[a-zA-Z0-9]+$/ alpha-num
or
/^\pL+$/u Uni alpha, /^\pN+$/u Uni num, /^[\pL\pN]+$/u Uni alpha-num
answered Mar 17, 2014 at 17:20
[PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8]
ctype_alpha — Check for alphabetic character[s]
Description
ctype_alpha[mixed $text]: bool
Parameters
textThe tested string.
Note:
If an int between -128 and 255 inclusive is provided, it is interpreted as the ASCII value of a single character [negative values have 256 added in order to allow characters in the Extended ASCII range]. Any other integer is interpreted as a string containing the decimal digits of the integer.
Warning
As of PHP 8.1.0, passing a non-string argument is deprecated. In the future, the argument will be interpreted as a string instead of an ASCII codepoint. Depending on the intended behavior, the argument should either be cast to string or an explicit call to chr[] should be made.
Return Values
Returns true if every character in text is a letter from the current locale, false otherwise. When called with an empty string the result will always be false.
Examples
Example #1 A ctype_alpha[] example [using the default locale]
The above example will output:
The string KjgWZC consists of all letters. The string arf12 does not consist of all letters.
See Also
- ctype_upper[] - Check for uppercase character[s]
- ctype_lower[] - Check for lowercase character[s]
- setlocale[] - Set locale information
Tyrunur ¶
13 years ago
It works if you set the locale correctly:
with this change you will get "yes" "yes"
[PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8]
ctype_alnum — Check for alphanumeric character[s]
Description
ctype_alnum[mixed $text]: bool
Parameters
textThe tested string.
Note:
If an int between -128 and 255 inclusive is provided, it is interpreted as the ASCII value of a single character [negative values have 256 added in order to allow characters in the Extended ASCII range]. Any other integer is interpreted as a string containing the decimal digits of the integer.
Warning
As of PHP 8.1.0, passing a non-string argument is deprecated. In the future, the argument will be interpreted as a string instead of an ASCII codepoint. Depending on the intended behavior, the argument should either be cast to string or an explicit call to chr[] should be made.
Return Values
Returns true if every character in text is either a letter or a digit, false otherwise. When called with an empty string the result will always be false.
Examples
Example #1 A ctype_alnum[] example [using the default locale]
The above example will output:
The string AbCd1zyZ9 consists of all letters or digits. The string foo!#$bar does not consist of all letters or digits.
See Also
- ctype_alpha[] - Check for alphabetic character[s]
- ctype_digit[] - Check for numeric character[s]
- setlocale[] - Set locale information
thinice at gmail dot com ¶
13 years ago
ctype_alnum[] is a godsend for quick and easy username/data filtering when used in conjunction with str_replace[].
Let's say your usernames have dash[-] and underscore[_] allowable and alphanumeric digits as well.
Instead of a regex you can trade a bit of performance for simplicity:
marcelocamargo at linuxmail dot org ¶
6 years ago
It is also important to note that the behavior of `ctype_alnum` differs according to the operating system. For UNIX-based operating system, if you pass a value that is not a string [or an overloaded object], independently of the value, it will always result in false. However, if we do the same on Windows, using, for example, -1 as literal [a minus and a number greater than 0], we'll have true as result.