Conditional vs logical

Question

What is the difference between logical and conditional operators? For example what is the difference between logical and (&) and conditional and (&&)?

Vulpes · Answer

Incidentally, Jeremy, if you were confused about my and Javeed's posts apparently talking about different things, then I should explain that there are two types of logical operators (&, | and ^): 1. Those that takes bool arguments (which I'm talking about); and 2. Those which take integer arguments (which Javeed's talking about). The latter are often referred to as bitwise operators because they are normally used to perform bit arithmetic. The former are seldom used because of the 'short circuiting' point. There is no such division for the conditional operators (&&, ||) which always take bool operands.

Vulpes · Answer

In the case of the logical operators, the second operand is always evaluated even if the overall value of the expression can be determined just by evaluating the first operand. So, if you have a & b, then b will still be evaluated even if a is false and a & b must therefore be false also. In the case of the conditional operators, 'short circuit' evaluation is used. If you have a && b and a is false, then the compiler doeesn't bother to evaluate b. This is quicker but might be a problem if expresssion b is a method call which has side effects which you were expecting to happen. For example, consider: bool c = a && MyMethod(b); //... bool MyMethod(bool b) { Console.WriteLine("Hello"); // side effect return b; } If a is false, then MyMethod() won't be called. However, it's not really good practice to do stuff like this anyway.

Javeed M Shaikh · Answer

& are bitwise operators while && are logical operators. Usually you'd want to use && for if statements and loops. The bitwise operators are for setting and checking bits within bitmasks.

Conditional vs logical

Answers (3)