Java Fundamentals · Arrays & Collections · Lesson 16 of 22
Arrays
Concept
Arrays
An array holds a fixed number of elements of the same type, accessed by a zero-based index, and its length never changes after creation.
By the end of this lesson
- Explain the core idea behind Arrays.
- Predict output before running a change.
- Test one realistic and one unusual input.
- Use the result to make the next decision.
How to study this page
- 1. Read one concept.
- 2. Change the example.
- 3. Run, compare, and explain.
- 4. Complete the challenge below.
ExampleRunnable
int[] scores = {90, 85, 78};
System.out.println(scores[0]);
System.out.println(scores.length);Self-check before continuing
Without looking at the example, describe what changes when you modify one input in Arrays. Then reopen the editor and prove your explanation with a small test.
You are ready to continue when you can predict, test, and explain the result.
Your turn
Create an array of 5 integers and print the last one using scores.length - 1.
Loading editor…
Console