oop c++

Question

What is meant by precedence rule for evaluation of expressions?

Answer 1

All C++ operators have two attributes. These two attributes are known a precedence and associativity.

Since you've asked about Precedence- So Precedence refers to the rank of an operator.

Like in mathematics we have BODMAS where the highest precedence is given to Bracket and lowest precedence is given to Subtraction. 

Similarly, C++ has an order of precedence and it decides how an expression will be evaluated. For example, we have an expression 

2 * 5 + 3  

Therefore, the above expression can be evaluated in two ways, first (2*5)+3 = 13 and second 2*(5+3) = 16 .

So we have two different answers, and in C++ first one is correct and * has higher precedence than +

Here's the table for precedence, Hope it helps. :)

Answer 2

precedence rules tells about the order of evaluation of an expression.For some expressions like 2+3*4 you can evaluate them in two ways either(2+3)*4 or 2+(3*4) precedence rules  describe you the correct way of evaluating an expression