The **`ctype_alnum` method** is used to check if all the characters of the text are alphanumeric.


#   
#  Syntax

```
ctype_alnum(mixed $text): bool
```

The `ctype_alnum` method returns a Boolean value.

> The alphanumeric characters are `A-Z, a-z, and 0-9`.

`ctype_alnum` returns `true` if and only if all of the characters in the text are alphanumeric. Otherwise, it returns `false`.

##  
## Example

<?php 

  $str = "abc";
  printAlphaNumeric($str);

  $str = "123ABccAAA";
  printAlphaNumeric($str);

  $str = "A B";
  printAlphaNumeric($str);

  function printAlphaNumeric($str){
    echo "The string is: ". $str. "\n";
    echo "Alphanumeric: ";
    var_dump(ctype_alnum($str));
    echo "---------\n";
  }

?>

In the code above: 

* We use the `ctype_alnum` method to check if the string contains only alphanumeric characters. 

* For the string `abc` and `123ABccAAA`, `ctype_alnum` returns `true`.

* For the string `A B`, the `ctype_alnum` method returns `false` because the string contains the space character, which is not an alphanumeric character.



What is the ctype_alnum method in PHP?

Syntax

Example