How to Run a Class Method Inside a Function in Java

Описание: A guide on how to run a class method within a function in Java, tailored for beginners transitioning from Python.
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This video is based on the question https://stackoverflow.com/q/74655125/ asked by the user 'tesla john' ( https://stackoverflow.com/u/18248287/ ) and on the answer https://stackoverflow.com/a/74655512/ provided by the user 'v_1' ( https://stackoverflow.com/u/20600414/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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How to Run a Class Method Inside a Function in Java

If you're someone new to Java and coming from a Python background, you might find yourself facing a few hurdles while coding. One common issue beginners encounter is trying to call a class method from within a function that's outside of the class scope. This can lead to confusing compiler errors, particularly when you are still getting acclimated to Java's object-oriented structure.

Let’s break down how to effectively use class methods within functions in Java, understanding the necessary syntax and structure along the way.

Understanding the Problem

As a new learner in Java, you may experience trouble when you observe the following:

Your code contains a method within a class that you want to call in another method.

You receive compiler errors suggesting that you need to alter the structure of your code—specifically, it may tell you to instantiate the method within the class.

To illustrate, consider the following Java code excerpt:

[[See Video to Reveal this Text or Code Snippet]]

Your goal is to run the reorder method within the read method, but it’s currently outside its scope as they belong to separate entities.

Solution Breakdown

Let’s go through the steps to correctly implement this in Java.

Step 1: Correct Class and Method Naming Conventions

Java is case-sensitive and follows specific naming conventions:

Class names should always start with an uppercase letter.

Method names should start with a lowercase letter.

Step 2: Use Static Methods

In Java, if you want to call a method from another class without needing to create an object of that class, declare the method as static. Thus, you can directly call it as ClassName.methodName().

Step 3: Create the Main Method

This is the entry point of any Java application. You'll want to set up a main method from where your program execution starts.

Step 4: Calling the Method

To run the reorder method from within the read method, ensure both methods are static, and you can call one from the other directly.

Here is the improved version of your code:

[[See Video to Reveal this Text or Code Snippet]]

Output

When you run this program, you should see the output:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

Transitioning from Python to Java can appear daunting, especially with its strict object-oriented approach. However, once you grasp the foundational concepts such as class and method accessibility, you'll find it much easier to manage your Java programs. With these structured steps, you're now equipped to run class methods within functions—just remember to keep your classes and methods logically organized and named correctly!

Happy coding!