CS 211: Introduction to Computer Programming II

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CS 211Introduction to Computer Programming II

• Instructor Brian M. Dennis
• Teaching Assistants
• Tom Lechner, Bin Lin, Rachel Goldsborough
• http//www.cs.northwestern.edu/bmd/cs211/

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Todays Topics

• Wrapping up the BitSet class
• C stream I/O

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Streams

• Already using them
• cout ltlt "foo"
• cin gtgt some_int
• Today, more sophisticated uses

• Participate in a hierarchy of classes
• Forward reference inheritance

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Stream Hierarchy
Templated Datatypes
basic_ios
basic_ostream
basic_istream
cin
cout
cerr
basic_iostream
clog
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Stream member functions

• ostream
• put, takes a char, returns ostream ref

• istream
• get, no args returns next char
• get, char ref stores next char
• get, char, size, delimeter
• up to terminator or buf size
• getline, no args,

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Stream member functions

• istream cont
• ignore
• putback
• peek

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Stream member functions

• include ltiostreamgt
• using stdcout
• using stdcin
• using stdendl
• int main()
• const int SIZE 80
• char buf1SIZE
• char buf2SIZE
• cout ltlt "Enter a sentence" ltlt endl
• cin gtgt buf1
• cout ltlt "\nThe string read with cin was" ltlt
  endl
• ltlt buf1 ltlt endl ltlt endl

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Stream member functions

• cin.get(buf2, SIZE)
• cout ltlt "The string read with cin.get was" ltlt
  endl
• ltlt buf2 ltlt endl
• cin.getline(buf2, SIZE)
• cout ltlt "\nThe sentence read with getline is"
  ltlt endl
• ltlt buf2 ltlt endl
• return 0

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Unformatted I/O

• output
• write, member function
• cout.write(buf)
• cout.write(buf, size)

• input
• read, member function
• cout.read(buf, sz)

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Stream manipulators

• Integer output base
• dec, oct, hex manip
• setbase member function
• Floating point precision
• of right digits displayed
• setprecision manip
• precision member function

• Field manipulations
• width member func, setw manip
• skipws, noskipws
• left, right
• showbase, noshowbase
• showpoint, noshowpoint
• scientific, fixed

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Stream flags

• cin.eof()
• Any input left?
• cin.fail()
• Error on input
• cin.bad()
• major error
• cin.good()
• bad, fail, eof all off

• cout.rdstate()
• Get flags as an integer
• cin.clear()
• reset flags
• operator!
• test badbit, failbit

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Thats a Wrap

• Reading
• 12.1 12.7