printf

Notes

• reference
• We will be using printf for some of our output.
  • This is part of the C library (so in c++ as well)
  • There are multiple versions of it printf, fprintf, sprintf
  • We only want printf for now.
• This is a variable argument function
  • The first argument is always a format string
  • Then for each conversion specifier in that format string an additional parameter is required.
• Conversion specifiers
  • The character %
  • optional :
    • - : justifies left, right justification is default
    • + : show the sign, negative numbers always have a sign
    • space: put a space place of the -, ignored for +
    • # : use an alternative output format
    • 0: pad with 0
  • optinal minimum field width n
  • .n optional precision for floating point types
  • conversion specifier
• The chart on the reference page is helpful.
• Some examples
  • Forget that, look at hello.cpp.