Cleanest way to toggle a boolean variable in Java?

AquaMethod_26237 0
Viewed 187818

Is there a better way to negate a boolean in Java than a simple if-else?

if (theBoolean) {
    theBoolean = false;
} else {
    theBoolean = true;
}
boolean java
9 Answers
theBoolean = !theBoolean;
zacherates_26030 
theBoolean ^= true;

Fewer keystrokes if your variable is longer than four letters

Edit: code tends to return useful results when used as Google search terms. The code above doesn't. For those who need it, it's bitwise XOR as described here.

Admin1

This answer came up when searching for "java invert boolean function". The example below will prevent certain static analysis tools from failing builds due to branching logic. This is useful if you need to invert a boolean and haven't built out comprehensive unit tests ;)

Boolean.valueOf(aBool).equals(false)

or alternatively:

Boolean.FALSE.equals(aBool)

or 

Boolean.FALSE::equals
user_24141890

The class BooleanUtils supportes the negation of a boolean. You find this class in commons-lang:commons-lang 

BooleanUtils.negate(theBoolean)
user_35127340 
Boolean original = null; // = Boolean.FALSE; // = Boolean.TRUE;
Boolean inverse = original == null ? null : !original;
user_68312270

If you're not doing anything particularly professional you can always use a Util class. Ex, a util class from a project for a class.

public class Util {


public Util() {}
public boolean flip(boolean bool) { return !bool; }
public void sop(String str) { System.out.println(str); }

}

then just create a Util object Util u = new Util(); and have something for the return System.out.println( u.flip(bool) );

If you're gonna end up using the same thing over and over, use a method, and especially if it's across projects, make a Util class. Dunno what the industry standard is however. (Experienced programmers feel free to correct me)

user_95916160
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