• Post Reply Bookmark Topic Watch Topic
  • New Topic
programming forums Java Mobile Certification Databases Caching Books Engineering Micro Controllers OS Languages Paradigms IDEs Build Tools Frameworks Application Servers Open Source This Site Careers Other all forums
this forum made possible by our volunteer staff, including ...
Marshals:
  • Campbell Ritchie
  • Liutauras Vilda
  • Bear Bibeault
  • Jeanne Boyarsky
  • Tim Cooke
Sheriffs:
  • Knute Snortum
  • Junilu Lacar
  • Devaka Cooray
Saloon Keepers:
  • Ganesh Patekar
  • Tim Moores
  • Carey Brown
  • Stephan van Hulst
  • salvin francis
Bartenders:
  • Ron McLeod
  • Frits Walraven
  • Pete Letkeman

C quiz questions  RSS feed

 
Ranch Hand
Posts: 43
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I need help with the following questions in
1)
output?
2)
I felt the answer would be 21,13,13,13 but the answer is 22,13,13,13.How b is coming as 22?
3)
I felt the answer should be 0, 1, 2, 3, 4, but is 0,0,1,2,3,4.How is the extra 0 coming?
4) why does 11 ^ 5 show 14
5)here a should have been 13(5*2+3) but it is coming as 25.How?
6)Why is this creating an infinite loop?
 
Ranch Hand
Posts: 93
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
1. output = 10
 
Mary Chellapa
Ranch Hand
Posts: 93
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
wow i could answer only first ... and i thought i was good in C.
 
Saloon Keeper
Posts: 9378
181
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Note that most of the answers are actually undefined, because C doesn't have proper rules for order of evaluation.

That said, here are some explanations using left-to-right evaluation.

1.)
z = x++ - --y * b / a;
z = 5++ - --(-10) * 2 / 4;
z = 5 - (-11) * 2 / 4;
z = 5 - (-22) / 4;
z = 5 - (-5);
z = 10;


2.)
b = a++ + ++a;
b = 10 + 12; // a = 12;
b = 22;

printf("%d,%d,%d,%d", b, a++, a, ++a);
printf("%d,%d,%d,%d", 22, 12, 13, 14);


3.)
myFunc(5) -> myFunc(4); printf("%d, ", 4);
myFunc(4) -> myFunc(3); printf("%d, ", 3);
myFunc(3) -> myFunc(2); printf("%d, ", 2);
myFunc(2) -> myFunc(1); printf("%d, ", 1);
myFunc(1) -> myFunc(0); printf("%d, ", 0);
myFunc(0) -> printf("%d, ", 0);


4.)
^ is the binary XOR operator. The calculation goes like this:

00001011 // 11
00000101 // 5
________
00001110 // 11 xor 5 = 14


5.)
Assignment operators (including compound assignment, like *=) have lowest precedence. The calculation goes:

a *= 2+3;
a *= 5;
a = 5*5;
a = 25;


6.)
You get an infinite loop because you're never incrementing the loop variable i. You're passing i to the increment function by value. The function increments a copy of i, and leaves the original variable like it was. A working increment function would look like this:You would call it like this:
 
sovan chatt
Ranch Hand
Posts: 43
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
@Stephan van Hulst thanks for the explanations!.
I have got 1 more question.

if I insert 358 and 453 what will x and y hold?
 
Sheriff
Posts: 21502
96
Chrome Eclipse IDE Java Spring Ubuntu VI Editor Windows
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
The correct answer to that is "try it yourself and find out".
 
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
Boost this thread!