Chapter 12, Problem 4SA

Character testing library functions:

• Library functions other than the string library functions are provided by programming language, which are intended to work with single characters.
• The support library functions are used for testing the value of the character.
• The function will return the Boolean result on testing; the result will be in “True” or “False” format.

isUpper(character):

• This function is used to validate whether the character given is upper case letter.
  • The function will return “True” if the character is in upper case.
  • The function will return “False” if the character is in lower case.

isLower(character):

• This function is used to validate whether the character given is lower case letter.
  • The function will return “True” if the character is in lower case.
  • The function will return “False” if the character is in upper case.

Example:

The below algorithm determines whether the first character in the string is in upper case and the present is in upper case, the character gets replaced by “0”.

//determine if the first character is in upper case

If isUpperCase (str[0]) Then

//replace the values present at the first position

Set str [0] = "0"

//end if

End If

Explanation:

• If condition validates the first position of the “str” is in upper case or not.
• If the condition becomes true, the character at positon “0” gets replaced with the character “0”.

Accessing string using subscript notation:

• The string that are accessed using the subscript notation uses subscript “0” to hold the first character and similarly till the last character.
• The first value the index value will be “0” and to find the last character use “length(variable)-1”.
• When a string is tried to access using an invalid subscript, it will throw an error.

Analysis of the given statement:

//declare and define a string

Declare string str= “Might”

//set the value located at the subscript 5 as defined

Set str[5] = “y”