What does the operator != mean?

The operator != is used in Java and many other programming languages to denote "not equal to." When you use this operator in a condition, it checks whether the two values on either side of it are different. If they are not equal, the expression evaluates to true; if they are equal, it evaluates to false. This is particularly useful in control flow statements, such as if statements or loops, where you want to make decisions based on whether two values are unequal.

For example, in a condition like if (a != b), the code inside the if block will execute only when the values of a and b are not the same. Understanding this operator is fundamental to making comparisons in Java and enabling the flow of logic in programs.