ARITHMETIC OPERATIONS ON CHARACTERS

ARITHMETIC OPERATIONS ON CHARACTERS

            C allows us to manipulate characters the same way we do with numbers. Whenever a character constant or a character variable is used in
 an expression, it is automatically converted into an integer value.

                                    x=’a’;

                                    printf(“%d\n”,x);

will display the number 97 at the screen. It is also possible to perform arithmetic operations on character constants and variables.

                                    x=’z’ – 1;

is a valid statement. In ASCII the value of ‘z’ is 122 and therefore the statement will assign the value 121 to variable x.

            We may also use character constants in relational expressions  for example, the expression

                                    ch>= ‘A’ && ch<=’Z’

would test whether the character contained in the variable character is an upper-case letter. We can convert a character digit
 to its equivalent integer value using the following relationship.

                                    x=character –‘0’;

                                      =ASCII of’5’ – ASCII of ‘0’

                                      =53 – 48

                                      =5.

atoi()

This function converts a string of digits into their integer values.

Syntax:           x = atoi(string);

             

Program

void main()

{

  Char number[6] = “2012”;

  int n;

  n=atoi(number);

  printf(“%d”,n);

}

Output

2012