| In this blog |
| constant |
| Types of constant |
| Integer constant |
| floating point constant |
| character constant |
| string constant |
| Declaring constant |
Constant
constants are indentifiers whose value is defined by the programmer at compiler time , its value can't be changed if you try to change the value of a constant then it will give you error.
Types of constant
an integer constant is type of constant of int type .
eg : 3412
if you want to make it unsigned place U or u as a suffix , l or L for long , UL or ul for unsigned long
eg : 31345ul (is integer of unsigned long)
if you want to make it ocatal or hexadecimal , use prefix 0 or (0x , 0X) respectively
eg: 07 (is integer of type octal) 0x7 (is integer of type hexadecimal)
by default it is +ve if you want to make it -ve place -ve sign.
eg : -8l (is -ve integer of long type)
floating point constant
floating point constant is type of float . A floating point constant consist of a integer part, decimal part and exponent part , it is not necessary that it will contain all these part
eg 7.54 , 7 e+2 , 3.54E-3
by default the floating point constant in +ve until you put -ve sign in front of it.
eg : -7.54 is -ve
by default all floating point constant is of type double until you put f or F (float ) and l or L (long)
eg : 7.54 ( dobule ) , 7.54f (float) , 7.54L (long)
character constant
char constant are single character that are enclose in single quotes (eg : 'a' ) , in memory character are stored in ascii values .
string constant
string constant are set of characters which are enclosed in double quotes (eg : "a" or "alpha") in string constant compiler automatically adds the null character('\0' ) at the end of string , so size of string "alpha" is 6 not 5 bytes.
Declaring constant
there are 2 methods for declaring constant
1) using keyword const
2) using #define (preprocessor directive)
const int a=5 (would initialize variable a with 5 )
#define pi 3.14 (here pi is not a variable it's just simple text)
Diffrence between using const keyword and using #define is that the 1st method can had varied scope but the 2nd is only global scoped .
Back to top(leave the comment down below if you have a doubt or suggestions ,thnks🙂)
Posts
No comments:
Post a Comment