Chapter 11, Arrays

• Read Chapter 11.1 and 11.2
• Caution: Arrays are old
  • Part of C.
  • They behave differently from most other data structures.
  • Do not generalize based on arrays.
• Caution: Arrays are dangerous
  • With arrays we will find brave new ways to crash your program.
  • Do not have array index out of bounds errors.
• Arrays are designed to hold a collection of homogeneous information.
• Arrays should be used any time you feel compelled to name variables value1, value2, value3 ... valuen
• Syntax
  • type identifier[const int expression]
  • const int expression is the size of the array
• Examples

  • int numbers[10];
    ColorT colors[MAX_COLORS];
    PlayerT players[MAX_PLAYERS];
           

• Caution:
  • The size of the array
    • Must be positive.
    • Must be known at compile time
    • Is usually declared as a constant.
• Accessing elements
  • An array with n elements is accessed via an index i, where 0 ≤ i < n
  • So an array with 10 elements is accessed with the index values 0 ... 9 inclusive.
  • Using a value less than 0, or greater or equal to the array size is an array index out of bounds error.
• Accessing an array with an out of bounds index error
  • May or may not cause a run time error
  • Will almost certainly result in erroneous data.
• You can not do most operations directly on arrays
  • Look at page 524 for a table.
  • But the only real operation is pass by value
    • And that is a lie, but it will work.
• Generate an array of players for Cthulhu Dice
• Print out the players for Cthulhu Dice