Could Java use a shorter operator to invert a boolean?
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MellowCedar47
Are there any plans to add a dedicated boolean-reversal operator to Java? The usual syntax is `boolVal = !boolVal;`, but repeating a long variable name can feel inconvenient. Something like `boolVal *= -1;`, `boolVal ^= true;`, or a new form such as `boolVal !=;` or `boolVal!!;` might express the intent more compactly. Is this worth considering, or would the unusual syntax and potential confusion make it too low-priority?
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There isn't a strong language-design case for this feature. Negating a boolean is already concise, and the cases where you need to mutate a flag in place aren't common enough to justify another special operator. Java also deliberately avoids treating booleans as numbers, so an arithmetic-style solution would be especially unintuitive.
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If the goal is clearer state management rather than fewer keystrokes, consider passing the desired boolean value into a method or builder instead of exposing a toggle operation. An explicit `enabled(boolean value)` style API is usually easier to read and reason about than behavior that depends on the object's current state.
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You can technically write `boolVal ^= true`, since XOR with true flips a boolean, but I would avoid it. Most Java developers will have to stop and think about what it means, whereas `boolVal = !boolVal;` communicates the operation immediately. A small helper method could be used if this pattern genuinely appears everywhere, though toggling hidden state through methods can also make APIs harder to understand.
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`*= -1` doesn't represent boolean negation. Java booleans aren't numeric values, and even in systems that treat true as 1 and false as 0, multiplying 1 by -1 produces -1, not false. The fact that nonzero values can be treated as truthy in some languages doesn't make that a good Java operation.
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A new operator would save only a few keystrokes while making the code less immediately readable. `boolVal = !boolVal;` is already clear, and a decent IDE can autocomplete even very long variable names. If the name is consistently painful to type, that may be a sign it should be shortened or renamed.
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AmberKite52: I would find `^= true` much more confusing than the normal assignment. Saving three characters isn't worth making maintainers mentally decode a bitwise-looking operation.