# C Programming - Expressions - Discussion

### Discussion :: Expressions - General Questions (Q.No.3)

3.

Which of the following is the correct usage of conditional operators used in C?

 [A]. a>b ? c=30 : c=40; [B]. a>b ? c=30; [C]. max = a>b ? a>c?a:c:b>c?b:c [D]. return (a>b)?(a:b)

Explanation:

Option A: assignment statements are always return in paranthesis in the case of conditional operator. It should be a>b? (c=30):(c=40);

Option B: it is syntatically wrong.

Option D: syntatically wrong, it should be return(a>b ? a:b);

Option C: it uses nested conditional operator, this is logic for finding greatest number out of three numbers.

 Afsheen said: (Jul 19, 2010) If b>c then b is true else c is true, so 1st b>c is evaluated and stored then a>c is evaluated and stored. now the whole expression is considered. Let us assume (i) in b>c case this stmnt is true so b is saved. (ii)in a>c case this stmnt is false so c is saved. now the expression is in the form max=a>b?c:b Now finally this is evaluated. you just assume the given stmnt as a>b?(a>c?a:c):(b>c?b:c). I hope you understood.

 Durga said: (May 11, 2011) I am not under stand please clear about it. In detailed because I don't know how to use ? opearator. So plese clear with a example how to use this operator.

 Ramu said: (Aug 1, 2011) Simply we have to think in general if..else format like if(a>b) { if(a>c) max is a else max is c } else if(b>c) max is b else max is c This is implemented , thinking in this we could easily analyse for greatest of 3 or 4 or 5 and so on easily I think so.

 Vishwas Pathak said: (Aug 28, 2011) Option A is also right i did it in the dev-c++ and i got first one as the answer.

 Vinutha said: (Sep 18, 2013) Can any one tell the correct syntax of all operators?

 Heena said: (Oct 18, 2013) max = a>b ? (a>C ? a : c) : (b>c ? b :c); Now I guess this statement is more clear.

 Shashank said: (Nov 19, 2013) What if in 'max = a>b ? (a>C ? a : c) : (b>c ? b :c)' c is greater than both a and b, then the equation will be max = a>b?c:c Then how would the statement be evaluated? though the answer is C, I want the steps compiler takes to evaluate it.

 DEVIPRIYA said: (Jun 9, 2014) Max = a>b?(a>c?a:c):(bb if condition is true then Max = (a>c?a:c). Else Max = (b

 Azhar said: (Jan 13, 2015) It is not terminated with ";" (option C).

 Merry John said: (Apr 15, 2015) I am agree with @Vishwas and @Azhar. Option A should be correct one.

 AdamK said: (Sep 6, 2015) Condition operators does not require strictly the "()"s. And there is a syntax error in option C, just like @Azhar mentioned. Between A and C, personally I tend to choose A.

 Mahalakshmi said: (Sep 13, 2015) I am not understand please explain clearly about it.

 Vibhor said: (Oct 23, 2015) Please post any example using this statement.

 Anshul Jain said: (Jan 8, 2016) Any one explain me. Why option A is wrong?

 Guddu said: (Apr 23, 2016) I think option C is completely right. Whereas option A having problem. main.c:6:18: error: lvalue required as left operand of assignment a>b ? c=30 : c=40; here "c=40" having problem.

 Apoorva said: (Aug 18, 2016) I think, both the option A and C are correct.

 Krishna said: (Sep 7, 2016) I have excuted the first option it is correct only.

 Prit said: (Sep 11, 2016) I can't understand. Why not to choose option A?

 Prit said: (Sep 11, 2016) I think both the option A and option C are true.

 Deepa said: (Mar 14, 2017) I did not understand the meaning of the operator ":" between the variables.

 Hemant said: (Jul 29, 2017) If they are being so specific about parenthesis. They should also include a semicolon in the end of their result mentioned. Because I believe the first option will also work.

 Mona said: (Aug 18, 2017) Option C is also not correct because there is no semi colon in the end of the statement.

 Sankar said: (Aug 28, 2017) Here the expression is evaluated from right to left.

 Reddy said: (Nov 27, 2017) C. Also a syntax error because at the semicolon has missed.

 Daniel said: (Dec 30, 2017) ; is missing in the C option.

 Sivarenjini said: (Jan 27, 2019) C option is also wrong. There must be semicolon at the end. Then only it can be considered as valid.

 Husain said: (Apr 2, 2020) A is not the correct answer. It will always generate the error of lvalue required instead righteous way to write statement A is; c=a>b?30:40; Of course, C, the option can also be termed wrong in syntax for not terminating it with a semicolon.