Difference Between Expressions and Statements in Java | Java Basics Explained

Learn the key differences between expressions and statements in Java. Understand how expressions produce values, statements perform actions, with examples and beginner-friendly explanations.

1️⃣ Expression

• Definition: An expression is a combination of variables, operators, and values that produces a single value.

• Key point: Expressions always return a value.

• Examples:

int a = 5;
int b = 3;

// Arithmetic expression
int sum = a + b;  // 'a + b' is an expression that produces 8

// Relational expression
boolean result = a > b;  // 'a > b' is an expression that produces true

// Logical expression
boolean check = (a > 2) && (b < 5);  // produces true

• Inside an expression, you can have:

  • Arithmetic operators: + - * / %
  • Relational operators: > < == != >= <=
  • Logical operators: && || !
  • Unary operators: ++ -- !

2️⃣ Statement

• Definition: A statement is a complete line of code that performs an action.

• Key point: Statements do not necessarily produce a value, but they execute an action.

• Examples:

int a = 5;             // declaration statement
int b = 3;             // declaration statement
int sum = a + b;       // expression inside a statement
System.out.println(sum);  // statement (prints value, action performed)
a++;                   // statement (increments a by 1)

• Types of statements in Java:

  • Expression statements: e.g., a = 5;
  • Control statements: e.g., if, for, while
  • Declaration statements: e.g., int x = 10;

3️⃣ Main Difference Table

🔑 Quick Tip

• Every expression can be part of a statement, but not every statement is an expression.

Example:

int a = 5 + 3; // '5 + 3' is expression, 'int a = 5 + 3;' is statement

📘 Related Topics

• [Java Expressions: Types, Examples & Practice Questions

  Complete Guide](/java/docs/expressions/)