Content |
 |
 |
The similarity of the assignment and equality comparison operators It is especially important to note that the equal sign = is not used for comparing whether two things are equal; you need ==. These are a major source of confusion for beginners. For example, if one wanted to define a loop that repeated while x was equal to `false', it would be wrong to write: while (x = false)Since what (x = false) does is to assign the value `false' to the variable x. It is not comparing the value inside variable x with the value `false'. The annoying thing about this is that the compiler will accept it, as it is perfectly valid Java syntax. It will simply give totally wrong and confusing results. This is because an assignment statement evaluates to a value itself. That is, writing while (x = false) is equivalent to: x = false; while (x) which is equivalent to: while (false) The code should be written as follows (i.e. using the test for equality operator ==): while (x == false)It is almost certain that you will make this mistake, more than once, during this module. Many people who have been programming professionally for years still make this mistake all the time. It is a poorly designed feature of the language, but retained to keep compatibility with C++ and C syntax.
. RITSEC - Global Campus
|
