cs110 lec 6

• Math, including:

  Numeric operators

  Precedence

  Exponents

  Integer division
• Numeric operators


  • = assignment operator
  • + addition
  • - subtraction
  • * multiplication
  • / division
  • % remainder
• Precedence


  Order of operations (PEMDAS) determines what to do first in an expression
• Exponents


  pow(a, b) is equivalent to a^b
• Integer division


  5 / 2 yields an integer 2, 5.0 / 2 yields a double 2.5, 5 % 2 yields the remainder 1
• string is not "built-in" to C++, it is in the C++ standard string library, so #include <string> is required to use it
• string


  Sequence of characters
• string operations


  • Comparing 2 string values
  • Searching a string for a particular character
  • Joining one string to another
• Input


  Extraction from the input stream (cin) using the >> operator
• Input is messy because users are messy, more details on input cleaning, good prompts, and dealing with users will come later
• Extraction operator cin >>


  Skips any leading whitespace, can have multiple extractions in one statement
• It is a common error to mix up the insertion << and extraction >> operators
• ComputeArea


  1. Read in radius

  2. Compute area

  3. Display the area
• ComputeAverage


  1. Read in multiple inputs

  2. Compute average
• DisplayTime


  Obtain hours and minutes from seconds
• ComputeChange


  Find the maximum number of dollars, quarters, dimes, nickels, and pennies for a given amount
• Common errors in C++ programming include:

  1. Undeclared/Uninitialized Variables and Unused Variables

  2. Integer Overflow

  3. Round-off Errors

  4. Unintended Integer Division

  5. Forgetting Header Files
• Compiling source code


  Preprocessor removes comments and handles preprocessor directives like #include
• Libraries like <iostream> and <string>

  Have an interface (header file) and implementation (other file), #include refers to the header file
• Comments


  Notes for the programmer, should be informative and plentiful, not just reiterating code