Session 6 If Statement

IF => Keyword


Normal Code ----> Above If Always Executed
if(condition (Statement) )
{
	body of if;  --> This part is Execute when Condition (Statement) is True 1 (Non-Zero)
				 --> This part is Skipped when Condition (Statement) is False 0
}
Normal Code ----> Below If Always Executed

Notes:
If Condition Construct :
Based on Some condition (Statement) Some part of Code is Executed.
Based on Some condition (Statement) Some part of Code is Skipped to achieve
this provision we need to go for if condition construct.

void main()
{
printf("A");
printf("B");
 if(3>2)  Condition True
 {
	printf("C");
	printf("D");
 }
printf("E");
printf("F");
}   Output : ABCDEF

void main()
{
printf("A");
printf("B");
 if(3>20)   Condition False
 {
	printf("C");
	printf("D");
 }
printf("E");
printf("F");
}  O/P : ABEF

void main()
{
printf("A");
printf("B");
 if( )
 {
	printf("C");
	printf("D");
 }
printf("E");
printf("F");
}   o/p : Error

void main()
{
printf("A");
printf("B");
 if(3)
 {
	printf("C");
	printf("D");
 }
printf("E");
printf("F");
}     O/P :  ABCDEF

void main()
{
int a=89;
printf("A");
 if(a)
 {
	printf("C");
 }
printf("E");
}  O/P: ACE

void main()
{
int a=89;
printf("A");
 if(a)
 {
	printf("C");
 }
printf("E");
}  O/P ACE
Example
void main()
{
printf("A");
 if(!2+7)
 {
	printf("B");
 }
printf("C");
}  O/P : ABC
--------------
void main()
{
printf("A");
 if(Condition Follow below)
 {
	printf("B");

 }
printf("C");
}

Condition()     O/P

33				ABC
0 				AC
2+8 			ABC
2-2.0			AC
!6-!4     		AC
5.9				ABC
7.8<=7.1		AC
9>9.9			AC


void main()
{
 printf("A");
 if(3>20)
 printf("B");
 printf("C");
}  O/P : AC
----> If Programmer does not provide {} body, then compiler by default
consider the First Semi-colon (;) as end of IF BODY

void main()
{
}    This is a Valid Program

void main()
{
	;
}     This is also a valid program

void main()
{
	printf("A");
	printf("B");
	if(5>64);   ----> End of IF Body
	printf("C");
	printf("D");
	printf("E");
}   O/P : ABCDE

If we provide Semicolon after If We will not get Error.

WAP to find Max of 2 int using (IF condition construct)

void main()
{
	int a,b,max;
	if(a>b)
	{	max=a;
	}
	if(b>a)
	{	max=b;
	}
	printf(" %d",max);
}

WAP to find Max of 2 int using Only one (IF condition construct)

void main()
{
int a=1,b=3,max;
max=b; 3
if(a>b)
{
  max=a;
}
printf("%d",max); 3
}
WAP to find Max of 2 int using Only one (IF condition construct) and 2 Variable
void main()
{
int a, b;
scanf("%d %d", &a , &b);

if(b>a)
{
a=b;
}
printf("%d", a);
}
WAP to find Max of 2 int using Only one (IF condition construct) and 2 Variable without losing values.

void main()
{
int a, b;
scanf("%d %d", &a , &b);

if(b>a)
{
printf("%d", b);
exit(0);  Stops the program   return;
}
printf("%d", a);
}
------------------------------------------------------------------
void main()
{
	printf("A");
	printf("B");
	if(0)
{
	;
}
	printf("C");
	printf("D");
	printf("E");
} O/P = ABCDE

1. void main()
{
	printf("A");
	if(5>64)
	printf("B");
	printf("C");
}
2. void main()
{
	printf("A");
	if(5>64)
	{
	printf("B");
	}
	printf("C");
}
3. void main(){printf("A"); if(5>64) printf("B");printf("C");}


---------------IF ELSE------------------
IF(statement)
{ IF BODY
}
else
{ ELSE BODY
}

Write A Program to find greatest of 2 int using IF ELSE
void main()
{
int a,b;
scanf("%d %d",&a,&b);

if(a>b)
{
printf("%d",a);
}
else
{
printf("%d",b);
}
}
Write A Program to find greatest of 3 int using IF ELSE

void main()
{
int a,b,c;

if(a>b)
{
	if(a>c)
	{
	printf("%d",a);
	}
}
else
{
	if(b>c)
	{
	printf("%d",b);
	}
	else
	{
	printf("%d",c);
	}

}
}

	if(a>b)
	if(a>c)
	printf("%d",a);//// if(a>c)
	else   //// if(a>c)
	if(b>c)
	printf("%d",b);////// if(b>c)
	else ////if(b>c)
	printf("%d",c); else

==============Actual Code
if(x)
if(y)
printf("A"); -----if(y)
else         -----if(y)
printf("B"); -----else
---------------------------11111111111111111111111111111--------
if(x)
{
    if(y)
    {
        printf("A");
    }
}
else
{
    printf("B");
}
---------------------------22222222222222222222222222222-----------------------------
if(x)
{
    if(y)
    {
    printf("A");
    }
    else
    {
        printf("B");
    }
}    Correct
***************************************************************************

void main()
{          ------>Not Valid
if(3>2)    ======> If Needs a statement. Conditional Construct needs a statement
}
************************************************************************
void main()
{
}   ----->Valid
-------------------------------------------------------
void main()
{
if(2+2)         ----->Valid
printf("A");    =====>expression in some value Zero - False Non-Zero- True
}
---------------------------------
void main()
{
if(!2+3)	----->Valid
printf("A"); -----> O/P: A
}
--------------------------------

void main()
{
if(1)			No of Statement : 2
printf("A");    No of Executable Statement : 1
else
printf("B");
}
--------------------------
void main()
{
if(12)
{
	if(2==2)
	{
		printf("A");
	}
	else  /////Belongs to if(2==2)
	{
		printf("B");
	}
}
else  /////if(12)
{
}
}
Note: Else always belongs to the nearby if body.

if(x)
if(t)
printf("A");    printf("A");  =>belongs to if(t)
				whole if(t)   =>if(x)
------------------------------------------------------
void main()
{
4-9; ---->  -5;
2+3; ====>  5
}
Operator does
1. Does its operation
2. Replace that expression with its result.
------------------------------------------------------
int x=10;
if(_____)
	printf("Hello %d",x);
else
	printf("Hai %d",x);

if            O/P
x==10         Hello 10
x=0           Hai 0
x=1           Hello 1
x==5          Hai 10
x=5           Hello 5
x             Hello 10
-------------------------------------
void main()
{
	int x;     ==> GV stored in x.
	if(x)
		printf("Hello %d ",x);
	else
		printf("Hai %d ",x);
}
                      O/P
x==GV ==> Zero        Hai 0
x==GV ==> Non Zero    Hello GV
************************************************
void main()
{
int x;
if(x = 0.5)   ////// x=0
	printf("Hello %d",x);
else
	printf("Hai %d",x);         Variable Convert the data type       FS (%d %c ) Does not convert data type
}  O/P  :    Hai 0
----------------------------------------------------

int a,b;
float c,d;
                 a     b      c        d
a=b=c=d=7.89;    7     7    7.89     7.89
d=c=b=a=7.89;    7     7     7.0     7.0
--------------------------------------------------------

void main()
{
printf("A");
if(23>4)
printf("B");
printf("C");      ///// Else body Must be very after of IF body ends
else             error: ‘else’ without a previous ‘if’
printf("D");
printf("E");
}