Java compilation and execution flow - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare the main method in Java.

Java

public class Main {
    public static void [1](String[] args) {
        System.out.println("Hello, world!");
    }
}

Drag options to blanks, or click blank then click option'

Amain

Bexecute

Crun

Dstart

Attempts:

3 left

💡 Hint

Common Mistakes

Using a method name other than 'main' for the entry point.

Forgetting the exact signature of the main method.

The main method in Java must be named main to be the entry point of the program.

2fill in blank

medium

Complete the command to compile a Java file named Main.java.

Java

javac [1]

Drag options to blanks, or click blank then click option'

AMain.class

BMain

CMain.java

Dmain.java

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to compile a .class file instead of a .java file.

Using wrong capitalization in the filename.

The javac command compiles Java source files with the .java extension.

3fill in blank

hard

Fix the error in the command to run the compiled Java program named Main.

Java

java [1]

Drag options to blanks, or click blank then click option'

AMain.java

BMain

CMain.class

Dmain

Attempts:

3 left

💡 Hint

Common Mistakes

Including the .class or .java extension when running the program.

Using lowercase 'main' instead of 'Main' if the class is named Main.

The java command runs the Java class by its class name without the .class extension.

4fill in blank

hard

Fill both blanks to complete the Java compilation and execution commands for a file named App.java.

Java

javac [1]
java [2]

Drag options to blanks, or click blank then click option'

AApp.java

Bapp

CApp

DApp.class

Attempts:

3 left

💡 Hint

Common Mistakes

Using the class file name in the compile command.

Using lowercase or incorrect class name in the run command.

To compile, use the source file App.java. To run, use the class name App without extension.

5fill in blank

hard

Fill all three blanks to complete the Java program structure and commands for a class named Demo.

Java

public class [1] {
    public static void [2](String[] args) {
        System.out.println("Demo program");
    }
}

// Compile with: javac [3]

Drag options to blanks, or click blank then click option'

ADemo

Bmain

CDemo.java

Ddemo

Attempts:

3 left

💡 Hint

Common Mistakes

Mismatching class name and file name.

Using incorrect method name for main.

Wrong capitalization in file name.

The class name is Demo. The main method is named main. The source file is Demo.java.