C Programming - Control Instructions - Discussion

When the compiler reaches the second n in
y == 1 ? n = 0 : n = 1;
It is convinced that the conditional expression is completely scanned. This expression evaluates to an R-value after which the compiler encounters an assignment operator (=). So essentially the compiler sees the above statement as
(y == 1 ? n = 0 : n) = 1;.
And the expression inside the brackets evaluates to an R-value. Since we can not place an R-value before the assignment operator (=), the compiler generates the error message "L-value required".

#include<stdio.h>
int main()
{
int n = 0, y = 1;
y == 1 ? n=0 : n=1;
if(n)
printf("Yes\n");
else
printf("No\n");
return 0;
}

Compile and run the following code in Turbo C or in GCC.
The conditional operator ?: has following form.
(condition)?true part : false part.

Thus, the value of n will be 0 not 1.

Hi friends....
y == 1 ? n=0 : n=1;
in the above statement we have 2 assignment statements after condition.
but the 2nd assignment statement should be in ( ).
because if there are two assignment statements after condition in ternary statement the second statement should be in ( )..
y == 1 ? n=0 : (n=1);
(according to test your c skills by Y.KANETHKAR)...

n=(y==1)?0:1 means check if y=1 or not. then y=1 means print n=0 or print n=1. Thus the way depends upon the y value, the given value need to store some where. In c lang, we assigned left hand side at which the given value will store autometically. Thus the way n is missing in given program.

LVALUE required means lift hand side value this error occurs when there is variable declared to store the returned value.
In following question y==1 is condition which is true but there is left hand side variable in order to store the returned value thus, lvalue error occurs .

y == 1?n=0:n=1; this statement evaluates like following
((y == 1) ? n) = 0 : n = 1;

== has higher precedence then ? : operator then assignment operator.
(y == 1) ? n evaluates to rvalue not lvalue, so the assignment operator doesn't work.

Hence lvalue is required.

There is an error in ?: ternary operator .

Here, y ==1 ? n =0 :n =1 evaluates to y==1 is true then it goes to n = 1 and assigned for it But n is not assigned to any of the variable. It gives an error which is Lvalue is required.

Problem : y==1? n=0:n=1;

Soln: There should be variable on a left-side of assignment operator to hold than it will give proper result.

int x;
x=(y==1?n=0:n=1);
where x = 1(true value returned)

Yes, @Sandya is right when run these code in GCC it also gives "NO" as a output and if you assign n=1 in if than it gives "YES" as a output so before If there is no bug.

y==1?n=0:n=1; <=> (y==1?n=0:n)=1;

Here, within parenthesis is an expression so, we can't assign value in an expression.