C - What is the output of the following program?#define SQR(x) (x*x)main(){ int

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C | Question 169 of 453

What is the output of the following program?

#define SQR(x) (x*x)

main()

{

int a,b=3;

a= SQR(b+2);

printf("%d",a);

}

A) 25
B) 11
C) Error
D) Garbage Value

Total Answers and Comments: 9

Last Update: March 05, 2009

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Best Rated Answer

—

Submitted by: vinayaka

The ans is B(11).

Since it passes like (3+2) to #define, where it calculates as

(3+2 * 3+2), as Ist preference is multiply & then addition, it evalvates as

(3+ 2 * 3 +2) = (3+6+2)=11.

Above answer was rated as good by the following members:
sittoop, sivaec61

January 14, 2006 02:02:53

vinayaka

RE:

The ans is B(11).

Since it passes like (3+2) to #define where it calculates as

(3+2 * 3+2) as Ist preference is multiply & then addition it evalvates as

(3+ 2 * 3 +2) (3+6+2) 11.

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2 0

Overall Rating: +2

February 08, 2006 12:39:21

keerthi

RE:

ans:a

because a sqr(5)

a 25;

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0 3

Overall Rating: -3

September 21, 2007 13:25:24

swati poddar

Member Since: September 2007 Contribution: 2

RE:

This problem is like this ex:-

#define q(Y)(Y*Y*Y)
main()
{
int a;
int b 3;
a q(++b);
printf("n a d b d" a b);
}

o/p >
a 216
b 6

solution:-
b 3 is taken by #define as
(++b*++b*++b)

++ > * .here ++ has higher preference than * so it will be taken as

4*4*4 216
so a 216

and b is incremended 3 times so b 3+1+1+1 6

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October 31, 2007 18:13:06

ven

Member Since: November 2005 Contribution: 10

RE:

ANS:a 25;

SQR(x) (X*X)

x b+2 3+2 5; X 5;
SQR(x) SQR(5) SQR(5*5) 25;

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0 1

Overall Rating: -1

February 20, 2008 15:48:35

sjulian

Member Since: February 2008 Contribution: 2

RE: What is the output of the following program?#define SQR(x) (x*x)main(){ int a,b=3; a= SQR(b+2); printf("%d",a);}

I go with vinayaka.

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February 21, 2008 02:02:34

mouthika

Member Since: February 2008 Contribution: 1

RE: What is the output of the following program?#define SQR(x) (x*x)main(){ int a,b=3; a= SQR(b+2); printf("%d",a);}

3+2*3+2 3+6+2(since * has higher precedence)
11

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February 22, 2008 03:16:14

vijoeyz

Member Since: September 2007 Contribution: 3

RE: What is the output of the following program?#define SQR(x) (x*x)main(){ int a,b=3; a= SQR(b+2); printf("%d",a);}

SQR(b+2) will be preprocessed as (3+2*3+2) which is 3+6+2 ( 11).

Thanks
Vijay Zanvar
http://faq.zanvar.in

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March 19, 2008 14:13:36

fkhanoom

Member Since: March 2008 Contribution: 4

RE: What is the output of the following program?#define SQR(x) (x*x)main(){ int a,b=3; a= SQR(b+2); printf("%d",a);}

SQR( b + 2 ) ( b+2 * b+2 ) ( 3+2 * 3+2 ) Now * has a higher precedence that +. Therefore (3+2 * 3+2 ) (3+6+2) 11.

In order to get the answer 25 SQR should have be defined as
#define SQR(x) (x)*(x).
Parenthesis have a higher precedence than *.

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March 05, 2009 15:09:55

mihir_void

Member Since: March 2009 Contribution: 3

RE: What is the output of the following program?#define SQR(x) (x*x)main(){ int a,b=3; a= SQR(b+2); printf("%d",a);}

Ans is B.

The macro SQR is expanded by the pre processor as follows:

a b+2*b+2;
the value of b being 3 the expression boils down to
a 3+2*3+2
hence a 11

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