Let us use character arrays fname, mname and lname to store the first name, middle name and last name of a person. The program given below first accepts the full name, i. e., values of fname, mname and lname using a scanf function. Then the name is printed in the desired abbreviated form using a printf function. The initial letters of fname and mname are printed using fname [0]and mname[0], respectively. The program is given below.

/* Write person’s name in abbreviated form */

#include <stdio.h>

int main()

{

    char fname[20], mname[20], lname[20]; /* person’s name */

      /* accept full name */

     printf(“Enter full name (first middle last): “);

     scanf(“%s %s %s”, fname, mname, lname);

      /* print abbreviated name */

     printf(“Abbreviated name: “);

     printf(“%c. %c. %s\n”, fname[0], mname[0], lname);

     return 0;

}

The program output is given below.

Enter full name (first middle last): Dinesh Kumar Thakur

Abbreviated name: D. K. Thakur

Let us use variable meters of type float to represent length in meters and variables feet and inches of type int and float, respectively, to represent length in the FPS system. Let us also use variable tot_inches of type float to represent the given length in inches. To convert the length in meters to the FPS system, we first determine tot_inches, i. e., given length in inches as

           tot_inches = meters * 100.0 I CM_PER_INCH;

where CM_PER_INCH is a symbolic constant, with a value 2.54, used to represent the centimeters per inch. Then the length in feet and inches is calculated as follows:

feet = tot_inches I  12;

inches = tot_inches – feet * 12;

As the variable feet is of type int, only the integer part of the division tot_inches/12 is assigned to it. The program is given below. It first accepts the value of meters and calculates the values of feet and inches as explained above. Finally, the values of feet and inches are printed.

/* Convert length in meters to feet and inches */

#include <stdio.h>

#define CM_PER_INCH 2.54

int main ()

{

   float meters;    /* length in meters */

   int feet;        /* length in feet */

   float inches;    /* and inches */

   float tot inches; /* total inches */

   printf(“Enter length in meters: “);

   scanf(“%f”, &meters);

   tot_inches =meters * 100.0 I CM_PER_INCH;

   feet = tot_inches I 12;

   inches = tot_inches – feet * 12;

   printf(”%.2fm = %d’ %.2f\”\n”, meters, feet, inches);

   return 0;

}

The program output is given below.

Enter length in meters: 1

1.00m = 3′ 3.37″

Take a close look at the last printf statement in this program. Note the use of the escape sequence \” to print a double quote in the output. Also note that we have omitted the minimum field width in the conversion specifications for variables meters· and inches as %. 2f. This causes the output values to be printed using minimum field width, i. e., closely spaced.

#include<ctype.h> 
 #include<stdio.h> 
 #include<conio.h> 
 void main() 
 { 
 char ch; 
 for(;;) 
 { 
 ch = getchar(); 
 if(ch=='.') break; 
 if(iscntrl(ch)) printf("%c is a control character\n", ch); 
 } 
 getch(); 
 } 
   
 OUTPUT:   
 a 
 a is a control character 

#include<ctype.h> 
 #include<stdio.h> 
 #include<conio.h> 
 void main() 
 { 
 char ch; 
 for(;;) 
 { 
 ch = getchar(); 
 if(ch==’.') break; 
 if(isalpha(ch)) printf("%c is a letter\n", ch); 
 } 
 getch(): 
 } 
   
 OUTPUT:   
 s 
 s is a letter 

#include<ctype.h> 
 #include<stdio.h> 
 #include<conio.h> 
 void main() 
 { 
 char ch; 
 for(;;) 
 { 
 ch = getchar(); 
 if(ch == '.’) break; 
 if(isxdigit(ch)) printf("%c is hexadecimal digit\n", ch); 
 } 
 getch(); 
 } 
   
 OUTPUT:   
 3 is hexadecimal digit 

A character is an uppercase letter if its value in the range ‘A’ to ‘ Z ‘ (both inclusive). The program segment given below tests whether a given character is an uppercase letter or not.

if (ch>= ‘A’ && ch<= ‘Z’)

printf(“%c is uppercase letter\n”, ch);

else printf(“%c is not uppercase letter\n”, ch);

This example uses an if-else statement to determine whether the character in variable ch is an ·uppercase letter or not. Note that if the condition in the if statement evaluates as false, we cannot assume the character to be a lowercase letter as it may be any other character such as a digit, punctuation symbol, space, etc.

We can rewrite the condition in the above if statement using the values of character constants ‘A’ and ‘z’ as (ch>= 65 && ch<= 90). However, this should be avoided for the reasons mentioned above. Also, recall that we can use the isupper library function to perform the test for uppercase characters and rewrite the if statement as if (isupper(ch))

#include<ctype.h>
#include<stdio.h>
#include<conio.h>
void main()
{
char ch;
for(;;)
{
ch = getchar();
if(ch == '.') break;
if(isupper(ch)) printf("%c is uppercase\n", ch);
}
getch();
}
 
OUTPUT:  
S
S is uppercase 

#include<ctype.h> 
 #include<stdio.h> 
 #include<conio.h> 
 void main() 
 { 
 char ch; 
 for(;;) 
 { 
 ch = getchar(); 
 if(isspace(ch)) printf("%c is white space\n", ch); 
 if(ch = I.') break; 
 } 
 getch(); 
 } 
   
 OUTPUT:   
 (Press spacebar) 
 is white space 

#include<ctype.h> 
 #include<stdio.h> 
 #include<conio.h> 
 void main() 
 { 
 char ch; 
 for(;;) 
 { 
 ch = getchar(); 
 if(ispunct(ch)) printf("%c is punctuation\n", ch); 
 if(ch = '.') break; 
 } 
 getch(); 
 } 
   
 OUTPUT:   
 . 
 . is punctuation 

#include<ctype.h> 
 #include<stdio.h> 
 #include<conio.h> 
 void main() 
 { 
 char ch; 
 for(;;) 
 { 
 ch = getchar(); 
 if(isprint(ch)) printf("%c is printable\n", ch); 
 if(ch == '.') break; 
 } 
 getch(); 
 } 
   
 OUTPUT:   
 i 
 i is printable 

#include<ctype.h> 
 #include<stdio.h> 
 void main() 
 { 
 char ch; 
 for(;;) 
 { 
 ch = getchar(); 
 if(ch = '.') break; 
 if(islower(ch)) printf("%c is lowercase\n", ch); 
 } 
 getch(); 
 } 
   
 OUTPUT:   
 s 
 s is lowercase 

#include<ctype.h> 
 #include<stdio.h> 
 #include<conio.h> 
 void main() 
 { 
 char ch; 
 for(;;) 
 { 
 ch = getchar(); 
 if(isgraph(ch)) printf("%c is printable\n", ch); 
 if(ch = '.') break; 
 } 
 getch(): 
 } 
   
 OUTPUT: 	 	 
 c 
 c is printable 

#include<ctype.h> 
 #include<stdio.h> 
 #include<conio.h> 
 void main() 
 { 
 char ch; 
 for(;;) 
 { 
 ch = getchar(); 
 if(ch == '.') break; 
 if(isdigit(ch)) printf("%c is a digit\n", ch); 
 } 
 getch(); 
 } 
   
 OUTPUT:   
 44 
 is a digit 

#include<ctype.h> 
 #include<stdio.h> 
 #include<conio .h> 
 void main() 
 { 
 char ch; 
 for(;;) 
 { 
 ch = getchar(); 
 if(ch == '.') break; 
 if(iscntrl(ch)) printf("%c is a control char\n", ch); 
 } 
 getch(); 
 } 
   
 OUTPUT:   
 2 
 is a control char 

#include<ctype.h> 
 #include<stdio.h> 
 #include<conio.h> 
 void main() 
 { 
 char ch; 
 for(;;) 
 { 
 ch = getchar(); 
 if(ch == '.') break; 
 if(isalpha(ch)) printf("%c is a letter\n", ch); 
 } 
 getch(); 
 } 
     
 OUTPUT:   
 Hii 
 H is a letter 
 i is a letter 
 i is a letter 

#include<ctype.h> 
 #include<stdio.h> 
 #include<conio.h> 
 void main() 
 { 
 char ch; 
 for(;;){ 
 ch = getc(stdin); 
 if(ch == '.') break; 
 if(isalnum(ch)) printf("%c is alphanumeric\n", ch); 
 } 
 getch(); 
 } 
   
 OUTPUT:   
 s4 
 s is alphanumeric 
 4 is alphanumeric 

An alphanumeric character is one that is either an uppercase or lowercase letter or a digit. The statement given below tests whether character ch is an alphanumeric character or not.

#include<ctype.h>
#include<stdio.h>
#include<conio.h>
void main()
{
char ch;
for(;;){
ch = getchar();
if(ch=='.')
break;
if(isalnum(ch)) printf("%c is alphanumeric\n", ch);
}
getch();
}
 
OUTPUT:  
a
a is alphanumeric 

#include<stdio.h> 
 #include<conio.h> 
 void main() 
 { 
 printf(“one\ntwo\nthree\nfour"); 
 getch(); 
 } 
   
 OUTPUT:   
 one 
 two 
 three 
 four 

#include<stdio.h> 
 #include<conio.h> 
 void main() 
 { 
 printf("1.\n"); 
 printf("2.\n"); 
 printf("3. "); 
 getch(); 
 } 
   
 OUTPUT:   
 1. 
 2. 
 3. 
   

#include<stdio.h>
#include<conio.h>
void main()
{
printf("\n \n\n Three lines");
printf("\n Special chars.\n\n\n\a\a");
printf("\t \tA Tab \n”);
printf("\t \tA control character?\n");
printf("\n\t\t\b\b more special chars?\n\n");
getch();
}
 
OUTPUT:  
Three lines
Special chars. A Tab A control character?  more special chars?
 

#include<stdio.h> 
 #include<conio.h> 
 void main() 
 { 
 printf("\nBe careful!!\a"); 
 getch(); 
 } 

#include<stdio.h> 
 #include<conio.h> 
 void main() 
 { 
 printf("\n\"It is a wise father that knows his own child.\" Shakespeare "); 
 getch(); 
 } 
   
 OUTPUT:   
 "It is a wise father that knows his own child.” Shakespeare 

#include<stdio.h> 
 #include<conio.h> 
 void main() 
 { 
 printf("\n 1 \n 2. "); 
 getch(); 
 } 
   
 OUTPUT:   
 1          2. 

#include<stdio.h> 
  
 #include<conio.h> 
  
 void main() 
  
 { 
  
 printf("%d ", 10); 
  
 printf("\r"); 
  
 getch(); 
  
 } 
   

#include<stdio.h> 
 #include<conio.h> 
 typedef signed char smallint; 
 void main(int) 
 { 
 smallint i; 
 for(i = 0; i < 10; i++) 
 printf("%d ", i); 
 getch(); 
 } 

#include<stdio.h> 
 #include<conio.h> 
 void main() 
 { 
 printf("\xA0 \xA1 \xA2 \xA3"); 
 getch(); 
 } 
   
 OUTPUT   
 a i o u  

#include<stdio.h> 
 #include<conio.h> 
 void main() 
 { 
 int i, j; 
 scanf("%o%x", &i, &j); 
 printf("%o %x", i, j); 
 getch(); 
 } 
   
 OUTPUT:   
 54 
 2 
 54 2 

#include<stdio.h> 
 #include<conio.h> 
 void main() 
 { 
 printf("%x %#x\n", 10, 10); 
 printf("%*. *f", 10, 4, 1234.34); 
 getch(); 
 } 
   
 OUTPUT:   
 a 0xa 
 1234.3400 

#include<stdio.h> 
 #include<conio.h> 
 void main() 
 { 
 int i = 10; 
 int j = 20; 
 int k = 30; 
 int n = 40; 
 n = scanf(" %d %x %0", &i, &j, &k); 
 printf("\n%d values read.", n); 
 printf("\ni = %d j = %d k = %d\n", i, j, k); 
 getch(); 
 } 
   
 OUTPUT:   
 1 
 0 values read. 
 i=10 j=20 k=30