Page 58 - Programming Microcontrollers in C

Program Flow and Control 43

{
int c,nn,no;
no=0;
nn=0;
while((c=getchar())!=EOF)
if(c>=’0'&&c<=’9')
nn++;
else
no++;
printf(“Digits=%d and other characters=%d\n”,nn,no);
return 0;
}
The statement

int c,nn,no;
declares the three variables c, nn, and no to be integers. You may
declare as many variables as you wish with a single declaration state­
ment. The next statements

no=0;
nn=0;

initialize the values of no and nn to 0. Variables declared with the
above sequence of instructions are automatic variables. These vari­
ables are not initialized by the compiler, and the programmer must
initialize them to a required value. Otherwise the variables will con­
tain garbage.
The code sequence
while((c = getchar()) !=EOF)
if(c>=’0' && c<=’9')
nn++;
else
no++;
comprise the while and its following statement. The if portion of
the statement tests the value of c and determines if it is a digit. A
character constant is identified as a specific value by placing the char­
acter value in single quotes. Therefore, the expression c>=’0'
determines if the character in the location c is greater than or equal