Constants in c:-

4-:real constants

write a program that swap two values
#include< stdio.h>
#include< conio.h>
void main()
int a,b,c;
printf("\nthe first number is %d",a);
printf("\nthe first number is %d",b);

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 -:


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-:
\n-:new line
\t-:tab distance
\a-:audible beep
escape sequences are specific codes that modify the output of simple printf function

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 -:

%ld-:long integer
%u-:unsigned integer
%lf-:long float(double)
%Lf-:long double

Comments in c-:

1-:single line
2-:double line(multi line)
Single line-:

void main()

multi line comment-:

void main()

types of errors in c-:

1->logical error->these error arise due to a logical mistke however these error is not notified
2->syntatical errors->when we make a mistake related to grammar of C these errors are called syntatical errors
3->run time errors ->these errors arise due to an exception or mathematical contratication.
4->linker errors->when function and keywords fail to relate with their header files these error are called linker errors