error: lvalue required as left operand of assignment

[tdk93]

I don't understand the error which the following program gives on compilation.

int a = 10,b;
    a >= 5 ? b = 100 : b= 200;
    printf("%d\n",b);

The error is "lvalue required as left operand of assignment"

[Irrelevant Elephant]

Try using brackets:

int a = 10,b;
(a >= 5) ? b = 100 : b= 200;
printf("%d\n",b);

[tdk93]

I understand that, but i want to know the reason why this error occurs, or what it means.

[Irrelevant Elephant]

I think it may be because your compiler is misunderstanding the order of operations, so gets confused

[Auroch]

The left side of an assignment operator must be an addressable expression.
Addressable expressions include the following:
numeric or pointer variables
structure field references or indirection through a pointer
a subscripted array element

http://docwiki.embarcadero.com/RADStudio/XE6/en/E2277_Lvalue_required_%28C%2B%2B%29

[cire]

In C, the ternary operator has a higher priority than = and your code is parsed thusly:

(a >= 5 ? b = 100 : b) = 200 ;

In C++ it will work as expected since both operators have the same priority.