# StringFilter

Filters all the elements in a string according to a specified callback

## Method Signature

```
StringFilter(list=[string], filter=[function:Predicate], delimiter=[string], includeEmptyFields=[boolean], multiCharacterDelimiter=[boolean], parallel=[boolean], maxThreads=[any], virtual=[boolean])
```

### Arguments

| Argument                  | Type                 | Required | Description | Default |
| ------------------------- | -------------------- | -------- | ----------- | ------- |
| `list`                    | `string`             | `true`   |             |         |
| `filter`                  | `function:Predicate` | `true`   |             |         |
| `delimiter`               | `string`             | `false`  |             | `,`     |
| `includeEmptyFields`      | `boolean`            | `false`  |             | `false` |
| `multiCharacterDelimiter` | `boolean`            | `false`  |             | `false` |
| `parallel`                | `boolean`            | `false`  |             | `false` |
| `maxThreads`              | `any`                | `false`  |             |         |
| `virtual`                 | `boolean`            | `false`  |             | `false` |

## Examples

### Full function

Return only the letters in the string that meet the callback condition.

[Run Example](https://try.boxlang.io/?code=eJzLSS0pSS0qVrBVUKqqCgyMUrLmSk7MyUlKTM4GimkoOOZVKmTmFShoKtjaKVRzcRallpQW5YGFbEF6gOprrbny83Iqo0CGBJcUZealu2XmAA3VUMiBGK6jADdS05qrvCizJNW%2FtKSgtERDAaoRKAwAnFYr7w%3D%3D)

```java
letters = "zzQQZ";
callback = ( Any inp ) => {
	return inp == "z";
};
onlyZs = StringFilter( letters, callback );
writeOutput( onlyZs );

```

Result: zzZ

### Member function

Return only the letters in the string that meet the callback condition.

```java
letters = "zzQQZ";
callback = ( Any inp ) => {
	return inp == "z";
};
onlyZs = letters.filter( callback );
writeOutput( onlyZs );

```

Result: zzZ

### Additional Examples

[Run Example](https://try.boxlang.io/?code=eJyNjTEKAjEQRWtziiFVAjZbhwiK7D0yMUhwzC6TCYuIdzfiWm1j%2Bz7%2FPUoiiSt40AExXk7aqRiIMMTb2EqUPJU%2BGjiWB%2BQyNwEL%2FgBPteMkjcsKfRdg%2F76c4lQbdQJVOJfrmKkXDNC3tIeN3jq1cJZ0bvfZwHq3P9GwMWmcUP%2FpGT70DSRqTHU%3D)

```java
letters = "abbcdB";
callbackFunction = ( Any input ) => {
	return input == "b";
};
result = stringFilter( letters, callbackFunction );
writeDump( result );
result1 = stringFilter( "bob", callbackFunction );
writeDump( result1 );

```

## Related

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