Tokens and Reserved Keywords in C language

Tokens and Reserved  Keywords in

 C language

Keywords are pre-defined words in a C compiler. Each keyword is meant to perform a specific function in a C program. Since keywords are referred names for compiler they can’t be used as variable name.

C language supports 32 keywords which are given below:

1. auto
2. int
3. const
4. short
5. break
6. long
7. continue
8. signed
9. double
10. struct
11. float
12. unsigned
13. else
14. switch
15. for
16. void
17. case
18. register
19. default
20. sizeof
21. char
22. return
23. do
24. static
25. enum
26. typedef
27. goto
28. volatile
29. extern
30. union
31. if
32. while

Tokens:

C tokens are the basic building blocks in C language which are constructed together to write a C program. Each and every smallest individual units in a C program are known as C tokens.

C tokens are of six types, they are,

1.     keywords (e.g. : int, while),

2.     Identifiers (eg: main, total),

3.     Constants (eg: 10,20),

4.     Strings (eg: “total”,”hello”),

5.     Special symbols (eg: (),{}),

6.     Operators (eg: +,-,/,*)

C token example program:

int main()

{

int x,y,total;

x=10, y=20;

total=x+y;

printf(“total=%d\n”,total);

}

where,

main – Identifier

(),{} – special symbols

int – keyword

x,y,total – Identifiers

main,int, x,y, total,{},() – tokens