C Programming Important Points 1

• Developed at AT & T’s Bell Laboratories of USA in 1972. Designed and written by Dennis Ritche. 
• Output Statement Syntax= printf("control string",variable);  //included in stdio.h Header file

          where, control string= format specifier, Message, Escape Seuence character.
          ex- printf("Hello");
                      Escape Sequence Character= \n(new line), \t(tab), \a(alert), \b(backspace)
                      Format Specifier= %d(integer), %f(float), %c(char)
          ex- printf("%d",c); // will print value of c

• Program to print Variable's Value

#include<stdio.h>

void main()

{

                int a=50;

float b=7.5;

char c='w';

printf("Value of a is %d",a);

printf("\nValue of a is %f",b);           // %.2f = 7.50  two digits after decimal

printf("\nValue of a is %c",c);

}

o/p=

         Value of a is 50

         Value of a is 7.500000

         Value of a is w

[Note- While using Ubantu, don't include conio.h Header File(U Can't use getch(),clrscr(),exit(),etc.)]

To Start Terminal press- Ctrl+Alt+t

To Write/Read Code type- $gedit FileName.c

To Complie and Run type- $gcc FileName.c -o AlternateFileName

                                              $./AlternateFileName

• Input statement syntax= scanf("Format specifier",&variable);
• Program for Addition

#include<stdio.h>

void main()

{

int a,b,c; 

printf("Enter 2 integer values  ");

scanf("%d %d",&a,&b);
                 //dont give space between last format specifer and double qoutes (%d")

// otherwise it will accept one more character from user
c=a+b;                                 

printf("Addition is %d",c);

}

 o/p=

             Enter 2 integer values 10 20

             Addition is 30