In

java.lang.Object
- princeton.introcs.In

```
public final class In
extends Object
```
Input. This class provides methods for reading strings and numbers from standard input, file input, URL, and socket.
The Locale used is: language = English, country = US. This is consistent with the formatting conventions with Java floating-point literals, command-line arguments (via Double.parseDouble()) and standard output (via System.out.print()). It ensures that standard input works the number formatting used in the textbook.
For additional documentation, see Section 3.1 of Introduction to Programming in Java: An Interdisciplinary Approach by Robert Sedgewick and Kevin Wayne.

Constructor Summary

Constructors
Constructor and Description
`In()` Create an input stream for standard input.
`In(File file)` Create an input stream from a file.
`In(Socket socket)` Create an input stream from a socket.
`In(String s)` Create an input stream from a filename or web page name.
`In(URL url)` Create an input stream from a URL.

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`close()` Close the input stream.
`boolean`	`exists()` Does the input stream exist?
`boolean`	`hasNextLine()` Does the input stream have a next line?
`boolean`	`isEmpty()` Is the input stream empty?
`static void`	`main(String[] args)` Test client.
`String`	`readAll()` Read and return the remainder of the input as a string.
`boolean`	`readBoolean()` Return the next boolean from the input stream, allowing "true" or "1" for true and "false" or "0" for false.
`byte`	`readByte()` Return the next byte from the input stream.
`char`	`readChar()` Read and return the next character.
`double`	`readDouble()` Return the next double from the input stream.
`static double[]`	`readDoubles()` Read doubles from standard input
`static double[]`	`readDoubles(String filename)` Read doubles from file
`double`	`readFloat()` Return the next float from the input stream.
`int`	`readInt()` Return the next int from the input stream.
`static int[]`	`readInts()` Read ints from standard input
`static int[]`	`readInts(String filename)` Read ints from file
`String`	`readLine()` Read and return the next line.
`long`	`readLong()` Return the next long from the input stream.
`String`	`readString()` Return the next string from the input stream.
`static String[]`	`readStrings()` Read strings from standard input
`static String[]`	`readStrings(String filename)` Read strings from a file

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - In
```
public In()
```
    Create an input stream for standard input.
  - In
```
public In(Socket socket)
```
    Create an input stream from a socket.
  - In
```
public In(URL url)
```
    Create an input stream from a URL.
  - In
```
public In(File file)
```
    Create an input stream from a file.
  - In
```
public In(String s)
```
    Create an input stream from a filename or web page name.
- Method Detail
  - exists
```
public boolean exists()
```
    Does the input stream exist?
  - isEmpty
```
public boolean isEmpty()
```
    Is the input stream empty?
  - hasNextLine
```
public boolean hasNextLine()
```
    Does the input stream have a next line?
  - readLine
```
public String readLine()
```
    Read and return the next line.
  - readChar
```
public char readChar()
```
    Read and return the next character.
  - readAll
```
public String readAll()
```
    Read and return the remainder of the input as a string.
  - readString
```
public String readString()
```
    Return the next string from the input stream.
  - readInt
```
public int readInt()
```
    Return the next int from the input stream.
  - readDouble
```
public double readDouble()
```
    Return the next double from the input stream.
  - readFloat
```
public double readFloat()
```
    Return the next float from the input stream.
  - readLong
```
public long readLong()
```
    Return the next long from the input stream.
  - readByte
```
public byte readByte()
```
    Return the next byte from the input stream.
  - readBoolean
```
public boolean readBoolean()
```
    Return the next boolean from the input stream, allowing "true" or "1" for true and "false" or "0" for false.
  - readInts
```
public static int[] readInts(String filename)
```
    Read ints from file
  - readDoubles
```
public static double[] readDoubles(String filename)
```
    Read doubles from file
  - readStrings
```
public static String[] readStrings(String filename)
```
    Read strings from a file
  - readInts
```
public static int[] readInts()
```
    Read ints from standard input
  - readDoubles
```
public static double[] readDoubles()
```
    Read doubles from standard input
  - readStrings
```
public static String[] readStrings()
```
    Read strings from standard input
  - close
```
public void close()
```
    Close the input stream.
  - main
```
public static void main(String[] args)
```
    Test client.

Class In

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

In

In

In

In

In

Method Detail

exists

isEmpty

hasNextLine

readLine

readChar

readAll

readString

readInt

readDouble

readFloat

readLong

readByte

readBoolean

readInts

readDoubles

readStrings

readInts

readDoubles

readStrings

close

main