Chapter%204%20INPUT%20AND%20OUTPUT%20OBJECTS

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Chapter 4INPUT AND OUTPUT OBJECTS
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Chapter 4

• The cout ObjectThe cout object is used to
  display information to the monitor and is
  contained in the iostream.h and iostream header
  files.

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Chapter 4

• Using the cout Objectcout ltlt item 1 ltlt item 2
  ltlt item 3 ltlt ltlt item n

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Chapter 4

• The cout Output Stream Flows to the System
  Monitor

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Chapter 4

• Using \n and endl

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Chapter 4

• The C Escape Sequences Used with cout
• \a Beep
• \b Backspace
• \n CRLF
• \r CR
• \t Horizontal tab
• \v Vertical tab
• \\ Backslash
• \' Single quote
• \ Double quote
• \? Question mark

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Chapter 4

• I/O Stream Manipulatorssetw(n) Sets field width
  to nsetprecision(n) Sets floating-point precis
  ion to nsetfill(n) Sets fill character to nws
  Extracts white space
  charactersendl Inserts a new line in the output
  stream, thenflush Flushes the output stream

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Chapter 4

• Setting the Field Widthcout ltlt setw(field
  width) ltlt output item

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Chapter 4

• Generating Decimal Point Valuescout.setf(iosfi
  xed )cout.precision(n)

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Chapter 4

• Generating Left-Justified Values cout.setf(ios
  fixed) cout.setf( iosleft)

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Chapter 4

• Generating Currency Valuescout.setf(iosfixed)
  cout.setf(iosshowpoint)cout.precision(2)

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Chapter 4

• Formatting Functions and Flags
  setf() Sets a formatting flag.
• unsetf() Unsets a formatting flag.
• precision(n) Sets decimal output to n decimal
  places.
• fixed Forces fixed decimal point output.
• left Forces left justification within field.
• right Forces right justification within field.
• scientific Forces exponential, e, output.
• showpoint Forces a decimal point to be displayed
  along with trailing 0s.(Used for currency
  outputs)
• showpos Forces a sign output for positive
  values.

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Chapter 4

• The cin ObjectThe cin object is used to read
  information from the keyboard and is contained in
  the iostream.h and iostream header files.

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Chapter 4

• The cin Input Stream Flows from the Keyboard

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Chapter 4

• Using the cin Object cin gtgt variable to be read
• Only one character is read at a time.
• White space (blanks, tabs, new lines, carriage
  returns, etc.) are ignored by cin when using the
  gtgt operator. However, white space can be read
  using different cin functions.
• Numeric values can be read as characters, but
  each digit is read as a separate character.

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Chapter 4

• Using get() and put() For Single Character Data
  cin.get(character variable) cout.put(character
  variable)

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Chapter 4

• Reading Strings Using getline()getline(input
  stream, string object, 'delimiting
  character)
• To avoid a potential problem, use the line cin
  gtgt ws before the cin.getline() statement.

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Chapter 4

• Opening an Input Fileifstream fin(file path")
• Opening an Output Fileofstream fout(file
  path")
• Opening an Input/Output Filefstream finout(file
  path)

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Chapter 4

• Processing an Open File if(!fileObject)
• cout ltlt "This file cannot be opened" ltlt
  endl
• exit(1)
• //END IF
• else
• while (Read Data Item From Input File )
• //BEGIN LOOP
• Process data item.
• //END LOOP
• //END ELSE