Chapter 18.2, Problem 14STE

Program Plan Intro

“map” template class:

• Type name for “map” of type “KeyType” elements to “T” elements  is

  “map<KeyType, T>” or “map<KeyType, T, Ordering>”

  • The “Ordering” is used to sort the values by using the key value.
  • If no “Ordering” is given, the ordering used is the binary operator “<”.
• The library header for “map” is “<map>”.
  • It places the definition in the “std” namespace.
• Defined type for “map” is given below:
  • “key_type” is used to represents the type of the key values.
  • “mapped_type” is used to indicate the type of the values mapped to.
  • “size_type” is used to represent the type of the size.
• The iterators are used in the “map” template class is “iterator”, “const_iterator”, “reverse_iterator” and “const_reverse_iterator”.
• The “map” template class uses the pair template class.
  • The pair template is used to store the association between the key and a data item.
  • Example: “map<string, int> numMap;”
    • Using the above example, user can add a mapping from “c++” to the number “8” by using “[]” operator.
    • Example for the above statement is “numMap["c++"] = 8;”.