# StringWriter
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
# StringWriter
```
open class StringWriter : Writer
```
|---|---|----------------------------------------------------------------------------------------------|
| [kotlin.Any](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-any/index.html) |||
| ↳ | [java.io.Writer](https://developer.android.com/reference/kotlin/java/io/Writer) ||
| | ↳ | [java.io.StringWriter](https://developer.android.com/reference/kotlin/java/io/StringWriter#) |
A character stream that collects its output in a string buffer, which can then be used to construct a string.
Closing a`StringWriter`has no effect. The methods in this class can be called after the stream has been closed without generating an`IOException`.
## Summary
| Public constructors ||
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---|
| [StringWriter](https://developer.android.com/reference/kotlin/java/io/StringWriter#StringWriter())`()` Create a new string writer using the default initial string-buffer size. |
| [StringWriter](https://developer.android.com/reference/kotlin/java/io/StringWriter#StringWriter(kotlin.Int))`(`initialSize:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`)` Create a new string writer using the specified initial string-buffer size. |
| Public methods ||
|--------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| open[StringWriter](https://developer.android.com/reference/kotlin/java/io/StringWriter#) | [append](https://developer.android.com/reference/kotlin/java/io/StringWriter#append(kotlin.Char))`(`c:` `[Char](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-char/index.html)`)` Appends the specified character to this writer. |
| open[StringWriter](https://developer.android.com/reference/kotlin/java/io/StringWriter#) | [append](https://developer.android.com/reference/kotlin/java/io/StringWriter#append(kotlin.CharSequence))`(`csq:` `[CharSequence](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-char-sequence/index.html)?`)` Appends the specified character sequence to this writer. |
| open[StringWriter](https://developer.android.com/reference/kotlin/java/io/StringWriter#) | [append](https://developer.android.com/reference/kotlin/java/io/StringWriter#append(kotlin.CharSequence,%20kotlin.Int,%20kotlin.Int))`(`csq:` `[CharSequence](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-char-sequence/index.html)?`, `start:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`, `end:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`)` Appends a subsequence of the specified character sequence to this writer. |
| open[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [close](https://developer.android.com/reference/kotlin/java/io/StringWriter#close())`()` Closing a`StringWriter`has no effect. |
| open[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [flush](https://developer.android.com/reference/kotlin/java/io/StringWriter#flush())`()` Flush the stream. |
| open[StringBuffer](https://developer.android.com/reference/kotlin/java/lang/StringBuffer.html#)! | [getBuffer](https://developer.android.com/reference/kotlin/java/io/StringWriter#getBuffer())`()` Return the string buffer itself. |
| open[String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html) | [toString](https://developer.android.com/reference/kotlin/java/io/StringWriter#toString())`()` Return the buffer's current value as a string. |
| open[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [write](https://developer.android.com/reference/kotlin/java/io/StringWriter#write(kotlin.CharArray,%20kotlin.Int,%20kotlin.Int))`(`cbuf:` `[CharArray](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-char-array/index.html)!`, `off:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`, `len:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`)` Write a portion of an array of characters. |
| open[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [write](https://developer.android.com/reference/kotlin/java/io/StringWriter#write(kotlin.Int))`(`c:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`)` Write a single character. |
| open[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [write](https://developer.android.com/reference/kotlin/java/io/StringWriter#write(kotlin.String))`(`str:` `[String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)!`)` Write a string. |
| open[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [write](https://developer.android.com/reference/kotlin/java/io/StringWriter#write(kotlin.String,%20kotlin.Int,%20kotlin.Int))`(`str:` `[String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)!`, `off:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`, `len:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`)` Write a portion of a string. |
| Inherited functions ||
|---|---|
| From class[Writer](https://developer.android.com/reference/kotlin/java/io/Writer) |------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | [Writer](https://developer.android.com/reference/kotlin/java/io/Writer)! | [nullWriter](https://developer.android.com/reference/kotlin/java/io/Writer#nullWriter())`()`
Returns a new`Writer`which discards all characters. The returned stream is initially open. The stream is closed by calling the`close()`method. Subsequent calls to`close()`have no effect. While the stream is open, the`append(char)`,`append(CharSequence)`,`append(CharSequence, int, int)`,`flush()`,`write(int)`,`write(char[])`, and`write(char[], int, int)`methods do nothing. After the stream has been closed, these methods all throw`IOException`. The[object](https://developer.android.com/reference/kotlin/java/io/Writer#lock:kotlin.Any)used to synchronize operations on the returned`Writer`is not specified.
| | [Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [write](https://developer.android.com/reference/kotlin/java/io/Writer#write(kotlin.CharArray))`(`cbuf:` `[CharArray](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-char-array/index.html)!`)`
Writes an array of characters.
| ||
| Inherited properties ||
|---|---|
| From class[Writer](https://developer.android.com/reference/kotlin/java/io/Writer) |-----------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | [Any](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-any/index.html)! | [lock](https://developer.android.com/reference/kotlin/java/io/Writer#lock:kotlin.Any)
The object used to synchronize operations on this stream. For efficiency, a character-stream object may use an object other than itself to protect critical sections. A subclass should therefore use the object in this field rather than`this`or a synchronized method.
| ||
## Public constructors
### StringWriter
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
StringWriter()
```
Create a new string writer using the default initial string-buffer size.
### StringWriter
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
StringWriter(initialSize: Int)
```
Create a new string writer using the specified initial string-buffer size.
| Parameters ||
|---------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `initialSize` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):The number of`char`values that will fit into this buffer before it is automatically expanded |
| Exceptions ||
|--------------------------------------|----------------------------|
| `java.lang.IllegalArgumentException` | If`initialSize`is negative |
## Public methods
### append
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun append(c: Char): StringWriter
```
Appends the specified character to this writer.
An invocation of this method of the form`out.append(c)`behaves in exactly the same way as the invocation
```kotlin
out.write(c)
```
| Parameters ||
|-----|-------------------------------------------------------------------------------------------------------------|
| `c` | [Char](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-char/index.html):The 16-bit character to append |
| Return ||
|--------------------------------------------------------------------------------------|-------------|
| [StringWriter](https://developer.android.com/reference/kotlin/java/io/StringWriter#) | This writer |
| Exceptions ||
|-----------------------|------------------------|
| `java.io.IOException` | If an I/O error occurs |
### append
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun append(csq: CharSequence?): StringWriter
```
Appends the specified character sequence to this writer.
An invocation of this method of the form`out.append(csq)`behaves in exactly the same way as the invocation
```kotlin
out.write(csq.toString())
```
Depending on the specification of`toString`for the character sequence`csq`, the entire sequence may not be appended. For instance, invoking the`toString`method of a character buffer will return a subsequence whose content depends upon the buffer's position and limit.
| Parameters ||
|-------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `csq` | [CharSequence](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-char-sequence/index.html)?:The character sequence to append. If`csq`is`null`, then the four characters`"null"`are appended to this writer. |
| Return ||
|--------------------------------------------------------------------------------------|-------------|
| [StringWriter](https://developer.android.com/reference/kotlin/java/io/StringWriter#) | This writer |
| Exceptions ||
|-----------------------|------------------------|
| `java.io.IOException` | If an I/O error occurs |
### append
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun append(
csq: CharSequence?,
start: Int,
end: Int
): StringWriter
```
Appends a subsequence of the specified character sequence to this writer.
An invocation of this method of the form`out.append(csq, start, end)`when`csq`is not`null`, behaves in exactly the same way as the invocation
```kotlin
out.write(csq.subSequence(start, end).toString())
```
| Parameters ||
|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `csq` | [CharSequence](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-char-sequence/index.html)?:The character sequence from which a subsequence will be appended. If`csq`is`null`, then characters will be appended as if`csq`contained the four characters`"null"`. |
| `start` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):The index of the first character in the subsequence |
| `end` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):The index of the character following the last character in the subsequence |
| Return ||
|--------------------------------------------------------------------------------------|-------------|
| [StringWriter](https://developer.android.com/reference/kotlin/java/io/StringWriter#) | This writer |
| Exceptions ||
|---------------------------------------|------------------------------------------------------------------------------------------------|
| `java.lang.IndexOutOfBoundsException` | If`start`or`end`are negative,`start`is greater than`end`, or`end`is greater than`csq.length()` |
| `java.io.IOException` | If an I/O error occurs |
### close
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun close(): Unit
```
Closing a`StringWriter`has no effect. The methods in this class can be called after the stream has been closed without generating an`IOException`.
| Exceptions ||
|-----------------------|-----------------------------------|
| `java.lang.Exception` | if this resource cannot be closed |
| `java.io.IOException` | If an I/O error occurs |
### flush
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun flush(): Unit
```
Flush the stream.
| Exceptions ||
|-----------------------|------------------------|
| `java.io.IOException` | If an I/O error occurs |
### getBuffer
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun getBuffer(): StringBuffer!
```
Return the string buffer itself.
| Return ||
|----------------------------------------------------------------------------------------------|------------------------------------------------|
| [StringBuffer](https://developer.android.com/reference/kotlin/java/lang/StringBuffer.html#)! | StringBuffer holding the current buffer value. |
### toString
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun toString(): String
```
Return the buffer's current value as a string.
| Return ||
|----------------------------------------------------------------------------------|----------------------------------------|
| [String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html) | a string representation of the object. |
### write
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun write(
cbuf: CharArray!,
off: Int,
len: Int
): Unit
```
Write a portion of an array of characters.
| Parameters ||
|--------|--------------------------------------------------------------------------------------------------------------------------|
| `cbuf` | [CharArray](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-char-array/index.html)!:Array of characters |
| `off` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):Offset from which to start writing characters |
| `len` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):Number of characters to write |
| Exceptions ||
|---------------------------------------|----------------------------------------------------------------------------------------------------------------|
| `java.lang.IndexOutOfBoundsException` | If`off`is negative, or`len`is negative, or`off + len`is negative or greater than the length of the given array |
| `java.io.IOException` | If an I/O error occurs |
### write
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun write(c: Int): Unit
```
Write a single character.
| Parameters ||
|-----|---------------------------------------------------------------------------------------------------------------------|
| `c` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):int specifying a character to be written |
| Exceptions ||
|-----------------------|------------------------|
| `java.io.IOException` | If an I/O error occurs |
### write
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun write(str: String!): Unit
```
Write a string.
| Parameters ||
|-------|--------------------------------------------------------------------------------------------------------|
| `str` | [String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)!:String to be written |
| Exceptions ||
|-----------------------|------------------------|
| `java.io.IOException` | If an I/O error occurs |
### write
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun write(
str: String!,
off: Int,
len: Int
): Unit
```
Write a portion of a string.
| Parameters ||
|-------|--------------------------------------------------------------------------------------------------------------------------|
| `str` | [String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)!:String to be written |
| `off` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):Offset from which to start writing characters |
| `len` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):Number of characters to write |
| Exceptions ||
|---------------------------------------|-----------------------------------------------------------------------------------------------------------------|
| `java.lang.IndexOutOfBoundsException` | If`off`is negative, or`len`is negative, or`off + len`is negative or greater than the length of the given string |
| `java.io.IOException` | If an I/O error occurs |