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# replaceMatches(in:options:range:withTemplate:)

Replaces regular expression matches within the mutable string using the template string.

```
func replaceMatches(in string: NSMutableString, options: NSRegularExpression.MatchingOptions = [], range: NSRange, withTemplate templ: String) -> Int
```

## Parameters

`string`

The mutable string to search and replace values within.

`options`

The matching options to use. See [`NSRegularExpression.MatchingOptions`](/documentation/Foundation/NSRegularExpression/MatchingOptions) for possible values.

`range`

The range of the string to search.

`templ`

The substitution template used when replacing matching instances.

## Return Value

The number of matches.

## Discussion

See [`Flag Options`](/documentation/Foundation/NSRegularExpression#Flag-Options) for the format of `templ`.

---

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