Read the first collection element.
Java: Access index zero only after establishing that the collection is nonempty.
public class Main {
public static void main(String[] args) {
int[] items = {5, 10, 15};
if (items.length > 0) System.out.println(items[0]);
}
}Expected output EXAMPLE
5
Details
Save as Main.java, compile with javac Main.java, and run java Main. Uses the Java 21 standard library.
Tested on Ubuntu 24.04.5 LTS · · openjdk 21.0.12.1 2026-08-18 · openjdk-21-jdk-headless 21.0.12.1+1-1~24.04.4
Test inputs, results and environment
The exact published code ran in a dedicated Linux test container with prepared inputs. Unprivileged snippet process, external networking disabled, read-only root filesystem, and a fresh temporary working directory. Fixtures and output records are isolated from the application database. Testing covers this example and its stated checks, not every input, operating system, or runtime version. The Linux container shares its host's kernel; this is not a native Windows test.
- Architecture / host kernel
- x86_64 / 6.18.54.1-microsoft-standard-WSL2
- Snippet identity / locale
- uid=65534, gid=65534 (unprivileged) / C.UTF-8
- Interpreter invocation
javac Main.java && java Main- Container image ID
sha256:32dc2d998158b6554c99b73b533f423696a0f3e31e8cbea9db10b5eee9a2fadd- Code SHA-256
6eb076f10ad1bd16d61957badb808a9a7927f179c8daad2d0d2ea6fa852f0d16- Dependencies
- openjdk-21-jdk-headless 21.0.12.1+1-1~24.04.4
Test input setup
These are the prepared inputs used by the test harness. See Details above for the prerequisites and how to run this example.
# No input files required.
Observed standard output
5
Exit code: 0. Standard error: empty. Validation: Exact stdout comparison. System-dependent values above are one recorded run.