How to strip out extra asterisks in a string using preg_replace()

Question

I know how to strip out extra spaces, dashes, and periods using preg_replace(), but I need to know what format below is correct for stripping out extra asterisks in a string. These lines of code work for stripping out extra spaces, dashes, and periods: ``` // Strips out extra spaces $string = preg_replace('/\s\s+/', ' ',$string); // Strips out extra dashes $string = preg_replace('/-+/', '-', $string); // Strips out extra periods $string = preg_replace('/\.+/', '.', $string); ``` Which of the following is correct for stripping out extra asterisks? ``` // Version 1: Strips out extra asterisks $string = preg_replace('/\*+/', '*', $string); // Version 2: Strips out extra asterisks $string = preg_replace('/*+/', '*', $string); ``` Thank you in advance. By the way, is there a list somewhere that shows all the characters that need to be escaped with a forward slash when using PHP?

Accepted Answer

Try this:

```
$string = preg_replace('/\*{2,}/', '*', $string);
```

This will replace any instances of multiple asterisks next to one another with one asterisk.

Or, if you wanted to just get rid of all asterisks:

```
$string = preg_replace('/[\*]+/', '', $string);
```

It's worth noting that * is a special character in regular expressions; so, you must escape it with a backslash.

Also, here's a good regex reference: http://www.regular-expressions.info/reference.html

Here's how you could combine multiple character replacements into one regex:

```
$string = preg_replace('/(\*|\.){2,}/', '$1', $string);
```

This will replace asterisks as well as periods.

How to strip out extra asterisks in a string using preg_replace()

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