Escape Sequence in C

An escape sequence in C language is a sequence of characters that doesn't represent itself when used inside string but has diffrent meaning as below.

List of Escape Sequences in C

Escape SequenceMeaning
\aAlarm or Beep
\fForm Feed
\nNew Line
\rCarriage Return
\tTab (Horizontal)
\vVertical Tab
\'Single Quote
\"Double Quote
\?Question Mark
\nnnoctal number
\xhhhexadecimal number

Escape Sequence Example:

#include <stdio.h>      
void main( ) {      
int number = 60;         

Constants in C

A constant is a value or variable that can't be changed in the program, for example: 10, 20, 'a', 3.4, "c programming" etc.
There are different types of constants in C programming

List of Constants in C

Decimal Constant10, 20, 450 etc.
Real or Floating-point Constant10.3, 20.2, 450.6 etc.
Octal Constant021, 033, 046 etc.
Hexadecimal Constant0x2a, 0x7b, 0xaa etc.
Character Constant'a', 'b', 'x' etc.
String Constant"c", "c program", "c in catchmecoder" etc.

2 ways to define constant in C

There are two ways to define constant in C programming.
  • const keyword
  • #define preprocessor
  • C constant keyword

    The const keyword is used to define constant in C programming.

    const float PI = 3.14;
    Now, the value of PI variable can't be changed.
    #include <stdio.h>  
    void main( ) {      
    const float PI = 3.14;       
    printf("The value of PI is: %f",PI);   
    The value of PI is: 3.140000

    C #define preprocessor

    The #define preprocessor is also used to define constant. we will learn later.
    Visit here for: to know more # define preprocessor.