a pair of number enclosed in parentheses

Question

Here is a block of code. Can anyone explain what it means to have a pair of numbers enclosed inside parentheses. (This is in C++.) ``` int a = 2, b = 2, c = 3, d = 1; if((a,b)<(c,d)) cout<<"case1"<<endl; else cout<<"case2"; ```

Accepted Answer

That's the comma operator; it evaluates the thing on the left, throws the result out, and returns the result on the right. Since evaluating an `int` variable has no side-effects, that `if` is semantically equivalent to

```
if(b < d)
```

a pair of number enclosed in parentheses

Solution

Problem