> For the complete documentation index, see [llms.txt](https://boxlang.ortusbooks.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://boxlang.ortusbooks.com/boxlang-language/reference/built-in-functions/string/rereplace.md).

# ReReplace

Uses a regular expression (regex) to search a string for a string pattern and replace it with another.

The search is case-sensitive.

## Method Signature

```
ReReplace(string=[string], regex=[string], substring=[string], scope=[string])
```

### Arguments

| Argument    | Type     | Required | Description                          | Default |
| ----------- | -------- | -------- | ------------------------------------ | ------- |
| `string`    | `string` | `true`   | The string to search                 |         |
| `regex`     | `string` | `true`   | The regular expression to search for |         |
| `substring` | `string` | `true`   | The string to replace regex with     |         |
| `scope`     | `string` | `true`   | The scope to search in (one, all)    | `one`   |

## Examples

### Strip Characters Using ReReplace

This example strips out all characters except a-z and 0-9.

[Run Example](https://try.boxlang.io/?code=eJwrSg1KLchJTE71y3dOLE7VUFAqSS0uUTA0MlZU0lFQio5L1K0y0LWMBXFA2NHHR0lB05oLAOdQDrs%3D)

```java
reReplaceNoCase( "test 123!", "[^a-z0-9]", "", "ALL" );

```

Result: test123

### Extract Characters Using Back Reference

Uses a back reference: \1 to extract the pattern contained within the parenthesis.

[Run Example](https://try.boxlang.io/?code=eJwrSg1KLchJTE71y3dOLE7VUFAyNDJOTEo2MTVT0lFQijbQtYzV1ohO1K2K1daE8EDiMYZKCprWXAA%2B8RAd)

```java
reReplaceNoCase( "123abc456", "[0-9]+([a-z]+)[0-9]+", "\1" );

```

Result: abc

### Additional Examples

[Run Example](https://try.boxlang.io/?code=eJwrL8osSXUpzS3QUAhyDUotyElMTvXLd04sTtVQUKqoSExKhhJKOgpKjk7OIColNU1JQVNB05qrHJ9uZ0cnxyDXEJAO5xonEOUONsTHhxjdyYlJiUWpJSAd0Y66UbGk6vdUyMkvS1XISvXxyUwtBmnMSs3J0aisAfI0Qdzk%2FPxskAzxZnkBDagkaBIAfCJliw%3D%3D)

```java
writeDump( REReplaceNoCase( "xxabcxxabcxx", "ABC", "def" ) );
writeDump( REReplaceNoCase( "CABARET", "C|B", "G", "ALL" ) );
writeDump( REReplaceNoCase( "cabaret", "[A-Z]", "G", "ALL" ) );
writeDump( REReplaceNoCase( "I love jeLLies", "jell(y|ies)", "cookies" ) );
writeDump( REReplaceNoCase( "I love Jelly", "jell(y|ies)", "cookies" ) );

```

## Related

* [Ascii](/boxlang-language/reference/built-in-functions/string/ascii.md)
* [CamelCase](/boxlang-language/reference/built-in-functions/string/camelcase.md)
* [Char](/boxlang-language/reference/built-in-functions/string/char.md)
* [CharsetDecode](/boxlang-language/reference/built-in-functions/string/charsetdecode.md)
* [CharsetEncode](/boxlang-language/reference/built-in-functions/string/charsetencode.md)
* [Compare](/boxlang-language/reference/built-in-functions/string/compare.md)
* [CompareNoCase](/boxlang-language/reference/built-in-functions/string/comparenocase.md)
* [Find](/boxlang-language/reference/built-in-functions/string/find.md)
* [FindNoCase](/boxlang-language/reference/built-in-functions/string/findnocase.md)
* [FindOneOf](/boxlang-language/reference/built-in-functions/string/findoneof.md)
* [Insert](/boxlang-language/reference/built-in-functions/string/insert.md)
* [JSStringFormat](/boxlang-language/reference/built-in-functions/string/jsstringformat.md)
* [Justify](/boxlang-language/reference/built-in-functions/string/justify.md)
* [KebabCase](/boxlang-language/reference/built-in-functions/string/kebabcase.md)
* [LCase](/boxlang-language/reference/built-in-functions/string/lcase.md)
* [Left](/boxlang-language/reference/built-in-functions/string/left.md)
* [ListReduce](/boxlang-language/reference/built-in-functions/string/listreduce.md)
* [LJustify](/boxlang-language/reference/built-in-functions/string/ljustify.md)
* [LTrim](/boxlang-language/reference/built-in-functions/string/ltrim.md)
* [Mid](/boxlang-language/reference/built-in-functions/string/mid.md)
* [ParagraphFormat](/boxlang-language/reference/built-in-functions/string/paragraphformat.md)
* [PascalCase](/boxlang-language/reference/built-in-functions/string/pascalcase.md)
* [QueryStringToStruct](/boxlang-language/reference/built-in-functions/string/querystringtostruct.md)
* [ReEscape](/boxlang-language/reference/built-in-functions/string/reescape.md)
* [ReFind](/boxlang-language/reference/built-in-functions/string/refind.md)
* [reFindNoCase](/boxlang-language/reference/built-in-functions/string/refindnocase.md)
* [ReMatch](/boxlang-language/reference/built-in-functions/string/rematch.md)
* [reMatchNoCase](/boxlang-language/reference/built-in-functions/string/rematchnocase.md)
* [RemoveChars](/boxlang-language/reference/built-in-functions/string/removechars.md)
* [RepeatString](/boxlang-language/reference/built-in-functions/string/repeatstring.md)
* [Replace](/boxlang-language/reference/built-in-functions/string/replace.md)
* [ReplaceList](/boxlang-language/reference/built-in-functions/string/replacelist.md)
* [ReplaceListNoCase](/boxlang-language/reference/built-in-functions/string/replacelistnocase.md)
* [ReplaceNoCase](/boxlang-language/reference/built-in-functions/string/replacenocase.md)
* [reReplaceNoCase](/boxlang-language/reference/built-in-functions/string/rereplacenocase.md)
* [Reverse](/boxlang-language/reference/built-in-functions/string/reverse.md)
* [Right](/boxlang-language/reference/built-in-functions/string/right.md)
* [RJustify](/boxlang-language/reference/built-in-functions/string/rjustify.md)
* [RTrim](/boxlang-language/reference/built-in-functions/string/rtrim.md)
* [Slugify](/boxlang-language/reference/built-in-functions/string/slugify.md)
* [SnakeCase](/boxlang-language/reference/built-in-functions/string/snakecase.md)
* [SpanExcluding](/boxlang-language/reference/built-in-functions/string/spanexcluding.md)
* [SpanIncluding](/boxlang-language/reference/built-in-functions/string/spanincluding.md)
* [SQLPrettify](/boxlang-language/reference/built-in-functions/string/sqlprettify.md)
* [StringBind](/boxlang-language/reference/built-in-functions/string/stringbind.md)
* [StringEach](/boxlang-language/reference/built-in-functions/string/stringeach.md)
* [StringEndsWith](/boxlang-language/reference/built-in-functions/string/stringendswith.md)
* [StringEndsWithNoCase](/boxlang-language/reference/built-in-functions/string/stringendswithnocase.md)
* [StringEvery](/boxlang-language/reference/built-in-functions/string/stringevery.md)
* [StringFilter](/boxlang-language/reference/built-in-functions/string/stringfilter.md)
* [StringMap](/boxlang-language/reference/built-in-functions/string/stringmap.md)
* [StringReduce](/boxlang-language/reference/built-in-functions/string/stringreduce.md)
* [StringReduceRight](/boxlang-language/reference/built-in-functions/string/stringreduceright.md)
* [StringSome](/boxlang-language/reference/built-in-functions/string/stringsome.md)
* [StringSort](/boxlang-language/reference/built-in-functions/string/stringsort.md)
* [StringStartsWith](/boxlang-language/reference/built-in-functions/string/stringstartswith.md)
* [StringStartsWithNoCase](/boxlang-language/reference/built-in-functions/string/stringstartswithnocase.md)
* [StripCR](/boxlang-language/reference/built-in-functions/string/stripcr.md)
* [Trim](/boxlang-language/reference/built-in-functions/string/trim.md)
* [UCase](/boxlang-language/reference/built-in-functions/string/ucase.md)
* [UCFirst](/boxlang-language/reference/built-in-functions/string/ucfirst.md)
* [Val](/boxlang-language/reference/built-in-functions/string/val.md)
* [Wrap](/boxlang-language/reference/built-in-functions/string/wrap.md)
* [YesNoFormat](/boxlang-language/reference/built-in-functions/string/yesnoformat.md)


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