Ch 5 · Operators & Expressions · Java
Topic 5 of 13 in Java — Complete Tutorial (Beginner) — 3 lessons.
Arithmetic Operators
Arithmetic operators perform calculations on numbers. Most match the symbols from maths class. The modulus operator % gives the remainder after division — 17 % 5 is 2. Java also has the increment ++ and decrement -- operators, which add or subtract one from a variable, used constantly in loops and counters. Remember the integer-division rule from Chapter 4: dividing two ints discards the decimals.
Comparison Operators
Comparison operators compare two values and always give a boolean. Note that == checks if two values are equal (a single = means assignment), and != checks if they are not equal. The rest — >, <, >=, <= — work just as in maths. These operators are how your program asks questions about its data and makes decisions.
Logical & Assignment Operators
Logical operators combine boolean conditions: && (AND) needs every condition true, || (OR) needs at least one true, and ! (NOT) flips a boolean. Assignment operators are shorthands for updating a variable: score += 10 means score = score + 10. These appear constantly whenever a value changes step by step or a decision depends on several factors.