#include< stdio.h> #include< conio.h> void main() { int a,b,c; clrscr(); a=4; b=5; c=a; a=b; b=c;
printf("\nthe first number is %d",a); printf("\nthe first number is %d",b); getch(); }
Working with constants.
A constant is a value that can never be changed throughout the entire program in C program. A constant can be declared by the following two ways.
Using const keyword -:Syntax-: const int a=6; Here, a becomes a constant of integer type having value 6, any change in this value will never be permitted.
Using #define method -: This kind of constant is symbolic constant. Syntax -: #define  a 6
Escape sequences
Escape sequences are specific codes that modify the output of simple printf function
Some Commonly used Escape Sequences are as follows.
\n -: New line
\t -: Tab distance
\a -: Audible beep
Control strings
Control strings are special codes used in printf statement especially for identifying the type of variable which is going to be displayed.
Following are the major control strings -: