Operator precedence is defined in the appropriate standard. The standards for C and C++ are the One True Definition of what exactly C and C++ are. So if you look closely, the details are there. In fact, the details are in the grammar of the language. For example, take a look at the grammar production … Read more
For operators, associativity means that when the same operator appears in a row, then which operator occurence we apply first. In the following, let Q be the operator a Q b Q c If Q is left associative, then it evaluates as (a Q b) Q c And if it is right associative, then it … Read more
Grouping (this is what non-comparison operators do): a + b + c means (a + b) + c Chaining (this is what comparison operators do): a < b < c means (a < b) and (b < c) Grouping left to right (this is the way things are grouped): 5 – 2 – 1 means … Read more
In any sane language, the ternary operator is right-associative, such that you would expect your code to be interpreted like this: $a = 2; echo ($a == 1 ? ‘one’ : ($a == 2 ? ‘two’ : ($a == 3 ? ‘three’ : ($a == 4 ? ‘four’ : ‘other’)))); # prints ‘two’ However, the … Read more
Change the first false by true. I know it seems stupid to have (true || true) but it proves your point. bool result = true || true && false; // –> true result = (true || true) && false; // –> false result = true || (true && false); // –> true
Grouping (this is what non-comparison operators do): a + b + c means (a + b) + c Chaining (this is what comparison operators do): a < b < c means (a < b) and (b < c) Grouping left to right (this is the way things are grouped): 5 – 2 – 1 means … Read more
Floating point addition is not necessarily associative. If you change the order in which you add things up, this can change the result. The standard paper on the subject is What Every Computer Scientist Should Know about Floating Point Arithmetic. It gives the following example: Another grey area concerns the interpretation of parentheses. Due to … Read more