Why is it that it's ok to increment character but not decrement with PHP?  

**PHP**

```
<?php
    $a = "a";
    echo $a. "<br>";  //a
    echo ++$a. "<br>";  //b
    echo --$a. "<br>";  //b
>

```

Is there a simple way as `--$a`to decrement a charrater?

There was a solution by using `chr`.