Word Matching Exercise for Section 4.6

isdigit(ch)
isalpha(ch)
isalnum(ch)
islower(ch)
isupper(ch)
tolower(ch)
toupper(ch)
returns true if the specified character is a lowercase letter.
returns the uppercase of the specified character.
returns true if the specified character is a digit.
returns true if the specified character is a letter.
returns true if the specified character is a letter or a digit.
returns true if the specified character is an uppercase letter.
returns the lowercase letter for the specified character.