Keywords

Learn all 50+ Java keywords with clear explanations, syntax, and examples. Perfect for beginners to understand the purpose and usage of each Java keyword.

This reference explains Keywords through its syntax, examples and boundaries. Use the linked course lessons when the surrounding Java concepts are unfamiliar.

In Java, keywords are reserved words that have a specific meaning to the compiler. These words cannot be used as identifiers (like variable names, class names, or method names). They define the structure and flow of a Java program.

There are 50+ Java keywords (as of Java 17), each playing a unique role. Let’s walk through each keyword with explanations and examples where applicable.

public class Demo {
  public static void main(String[] args) {
    int count = 5;

    for (int i = 0; i < count; i++) {
      if (i == 3) {
        continue; // skip 3
      }
      System.out.println("i = " + i);
    }
  }
}

i = 0
i = 1
i = 2
i = 4

public class ExceptionDemo {
  public static void main(String[] args) {
    try {
      int result = 10 / 0;
    } catch (ArithmeticException e) {
      System.out.println("Cannot divide by zero!");
    } finally {
      System.out.println("Finally block always runs.");
    }
  }
}

Cannot divide by zero!
Finally block always runs.

Check the example’s types, inputs and documented behavior before copying it into an application. Some APIs require external libraries, files or platform services; consult their setup notes.

Related explanations: Java Data Types - Primitive and Non-Primitive, Java Class - Blueprint of Objects, Exceptions in Java Introduction.

Supporting documentation: Official Java learning guide.