Assignment and increment
- Java course
- Beginner
- Lesson 28/116
- 4 min
Learn =, +=, ++, -- assignment and increment operators.
Assignment and increment operators
= does assignment. Compound assignment operators like +=, -=, *=, /= combine the operation and the assignment.
int x = 10;
x += 5; // x = x + 5 → 15
x -= 3; // x = x - 3 → 12++ and -- increment or decrement a variable by 1. They can come before (++x) or after (x++) the variable. Pre-increment increments then uses; post-increment uses then increments.
int x = 5;
int y = x++; // y = 5, then x = 6
int z = ++x; // x = 7, then z = 7Practice Use compound assignment
Write a Main class with a main method. Assign 10 to int total. Do total += 5 and total++. Print total with println.
Sample solution
public class Main {
public static void main(String[] args) {
int total = 10;
total += 5;
total++;
System.out.println(total);
}
}Expected output
16
Pre vs post increment
++x and x++ look the same but behave differently. ++x (pre-increment) increments then uses; x++ (post-increment) uses then increments.
int x = 5;
int a = ++x; // x = 6, a = 6
int b = x++; // b = 6, then x = 7This distinction matters in loop counters and assignments. Standalone x++; or ++x; give the same result.
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 Match the assignment operators
| Term | Meaning |
|---|---|
= |
Assignment |
+= |
Add assign |
++ |
Increment |
-- |
Decrement |
2 Complete the compound assignment
int x = 10; x ____= 5;int x = 10; x += 5;Explanation: += combines addition with assignment.
3 What is the result of int x = 5; int y = x++;?
- y = 6, x = 6
- y = 6, x = 5
- y = 5, x = 5
- y = 5, x = 6 Correct answer
Explanation: x++ first assigns 5 to y, then makes x 6.