Booleans in Java

1 exercise

About Booleans

Booleans in Java are represented by the boolean type, which values can be either true or false.

Java supports three boolean operators:

  • ! (NOT): negates the boolean
  • && (AND): takes two booleans and results in true if they're both true
  • || (OR): results in true if any of the two booleans is true

The && and || operators use short-circuit evaluation, which means that the right-hand side of the operator is only evaluated when needed.

These are also known as conditional or logical operators. ! is sometimes classified as a bitwise operation in the documentation but it has the conventional NOT semantics.

true || false // => true
false || false // => false
false || true // => true
true && false // => false
true && true // => true
!true // => false
!false // => true

The three boolean operators each have a different operator precedence. As a consequence, they are evaluated in this order: not first, && second, and finally ||. If you want to 'escape' these rules, you can enclose a boolean expression in parentheses (()), as the parentheses have an even higher operator precedence.

!true && false   // => false
!(true && false) // => true
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