GATE CSE
First time here? Checkout the FAQ!
x
+3 votes
70 views

asked in Programming by Active (1.3k points)   | 70 views
-121. range of character -128 to 127. after 127 , -128 comes and so on. it is cyclic. so add 10 to 127 will give -121

Output would most likely be -121. However, there is a catch. Please check this.

2 Answers

+3 votes
Best answer

As per C standard, there are three distinct types.

  1. a char
  2. a signed char
  3. an unsigned char

 gcc by default takes plain char as signed char. in a 2's complement machine following things would happen when ever char value exceeds $127$.

  • Likewise in the above program, it will print $-121$

 


The following program will stop for an unsigned char. But loop forever for a signed char

 

#include <stdio.h>
int main() {
	unsigned char c = 0; // loops forever for char c = 0;
	while(c < 130) {
		printf("hello\n");
		c++;
	}
	return 0;
}

 

answered by Veteran (43.8k points)  
selected by
+1 vote

We should know the below concepts before solving this question:-

Concept1:- char c ; means by default signed char c;

Conecpt2:- C Follows 2's Complement representation.

Concept3(Follows from Concept2):-(Imp):- Whatever U store it stored in Binary Number but while retrieval  it gives 2's Complement of Binary Number

So here c=125+10=135

(135)10 = (1000 0111)

So in memory 1000 0111 will store which is binary equivalent of 135

but when we will print char C means ->>( 1000 0111 )it will give us the 2's Complement representation of c which is -121.

Hence -121 is Ans.

 

answered by Veteran (16.3k points)  
edited by

Related questions

+4 votes
1 answer
2
asked in Programming by Rohan Mundhey Loyal (4.2k points)   | 82 views
0 votes
1 answer
3
asked in Programming by Sanjay Sharma Veteran (41.3k points)   | 50 views


Top Users Mar 2017
  1. rude

    4758 Points

  2. sh!va

    3014 Points

  3. Rahul Jain25

    2910 Points

  4. Kapil

    2636 Points

  5. Debashish Deka

    2450 Points

  6. 2018

    1514 Points

  7. Vignesh Sekar

    1422 Points

  8. Akriti sood

    1322 Points

  9. Bikram

    1286 Points

  10. Sanjay Sharma

    1076 Points

Monthly Topper: Rs. 500 gift card

21,494 questions
26,815 answers
61,058 comments
23,068 users