Reserved Keywords

Reserved Keywords of C Programming
auto	default		float	register	struct		volatile
break	do		for	return	switch		while
case	double		goto	short	typedef
char	else		if	signed	union
const	enum		int	sizeof	unsigned
continue	extern		long	static	void
Reserved Keywords of C Programming
auto		float				struct
break		for				switch
case		goto				typedef
char		if				union
const		int				unsigned
continue		long				void
default		register				volatile
do		return				while
double		short
else		signed
enum		sizeof
extern		static

Data Types

int : Integer type के variable को declare करने के लिए 'int' data type का इस्तेमाल किया जाता है | for e.g. int a=0; 'a' is integer variable. char : Character type के variable को declare करने के लिए 'char' data type का इस्तेमाल किया जाता है | for e.g. char ch='Hello'; 'ch' is character variable. double : Double type के variable को declare करने के लिए 'double' data type का इस्तेमाल किया जाता है | इसका उपयोग ज्यादातर नहीं होता , इसके बदले में float data type का इस्तेमाल होता है | for e.g. double num=3.5; 'num' is double variable. float : Floating type के variable को declare करने के लिए 'float' data type का इस्तेमाल किया जाता है | for e.g. float var=1.20; 'var' is floating variable.

Loops	Example	Output
Do...While Loop	void main(){ int i=0; do{ printf("%d\n",i); i++; } while(i<5); }	0 1 2 3 4
For Loop	void main(){ int i; for(i=0; i<5; i++){ printf("%d\n",i); } }	0 1 2 3 4

Decision Control/Statements	Example	Output
if...else Loop	void main(){ int i=10; if(i==10){ printf("i is equal to 10"); } else{ printf("i is not equal to 10"); } }	i is equal to 10
switch..case..default	void main(){ switch(2){ case 1: printf("expression is 1"); break; case 2: printf("expression is 2"); break; default: printf("unknown expression"); }	expression is 2

Storage Classes	Example	Output
auto	void main() { auto int num = 10 ; { auto int num = 5 ; printf("num : %d\n",num); } printf("num : %d",num); }	num : 5 num : 10
extern	extern int num; void main() { printf("num value comes from General File is %d", num); }	num value comes from General File is 10
register	void main() { register int num=1; printf("These Number is stored in CPU's register\n"); printf("%d ",num); }	These Number is stored in CPU's register 1
static	function(){ static int num = 1; printf("%d",num); num++; } void main() { int i; for(i=0; i<10; i++){ printf("\n"); function(); } }	1 2 3 4 5 6 7 8 9 10

Jumping Statements	Example	Output
goto	void main(){ int num1, num2, num3; char ch; yes : printf("Enter two values\n"); scanf("%d%d",&num1, &num2); num3 = num1 + num2 ; printf("Addition of %d and %d is %d\n", num1, num2, num3); printf("\nDo you want to continue y(yes) or n(No)"); scanf(" %c",&ch); if(ch=='y'){ goto yes; } else if(ch=='n'){ goto no; } else{ printf("You entered other key"); } no : printf("Do you want to exit ?, Press Enter"); }	Enter two values 5 6 Addition of 5 and 6 is 11 Do you want to continue y(yes) or n(No)n Do you want to exit ?, Press Enter
continue	void main(){ int i=0; while ( i < 20 ){ printf("value of i is %d\n", i); i++; if ( i == 10 ) printf("Continued Values\n"); continue; } }	value of i is 0 value of i is 1 value of i is 2 value of i is 3 value of i is 4 value of i is 5 value of i is 6 value of i is 7 value of i is 8 value of i is 9 Continued Values value of i is 10 value of i is 11 value of i is 12 value of i is 13 value of i is 14 value of i is 15 value of i is 16 value of i is 17 value of i is 18 value of i is 19

struct

struct Student { char stud_name[30]; }; void main(){ struct Student info; strcpy( info.stud_name, "Pradeep Rana"); printf( "Student name is %s ", info.stud_name); } Output : Student name is Pradeep Rana

return

Number(){ int a=10, b=5, c; c = a + b; return c; } void main(){ printf("Addition of a and b is %d",Number()); } Output : Addition of a and b is 15

typedef

void main(){ typedef int num; num num1; printf("Enter value of num1 "); scanf("%d", &num1); printf("Value of num1 is %d", num1); } Output : Enter value of num1 5 Value of num1 is 5

union

union Student { char stud_name[30]; }; void main(){ union Student info; strcpy( info.stud_name, "Pradeep Rana"); printf( "Student name is %s ", info.stud_name); } Output : Student name is Pradeep Rana

const

void main(){ const int num=1; printf("num = %d",num); } Output : num = 1

enum	enum Days {Sun, Mon, Tue, Wed, Thu, Fri, Sat }; void main() { printf("%d, %d, %d, %d, %d, %d, %d",Sun, Mon, Tue, Wed, Thu, Fri, Sat); } Output : 0, 1, 2, 3, 4, 5, 6

sizeof

void main(){ printf("%d",sizeof(int)); } Output : 4