Java Methods

Introduction

In this lesson of Java course, we will learn about the Java methods. One of the key features of Java is the ability to create methods, which are self-contained blocks of code that perform a specific task. In this article, we’ll explore what Java methods are, how to declare and use them, and the benefits of using methods in Java programming.

1. What are Java Methods?

Java methods are blocks of code that perform a specific task. They are also known as functions or procedures in other programming languages. There are two types of methods in Java:

• User Defined Methods.
• Standard Methods

User-defined methods are created by the programmer, while standard methods are provided by the Java API. The purpose of methods in Java programming is to break down a large program into smaller, more manageable pieces. By doing this, it becomes easier to write and maintain code. Methods also promote code re-usability, as a programmer can use the same method in different parts of their program without having to rewrite the code.

2. How to Declare Java Methods

The syntax for declaring a Java method is:

access_modifier return_type method_name(parameter_list) {
    // method body
}

The access modifier determines the visibility level of a method, and it can be public, private, protected, or no modifier. On the other hand, the return type shows the data type of the value that the method returns, where the void return type specifies that the method does not return a value. The method name refers to the name of the method, while the parameter list specifies the input parameters that the method takes. Here are some examples of simple Java methods with different return types:

public class MyClass {
    public void printHello() {
        System.out.println("Hello");
    }

    public int add(int a, int b) {
        return a + b;
    }

    public boolean isPositive(int num) {
        return num > 0;
    }
}

3. Java Method Return Type

The return type of method is the data type of the value that the method returns. If the method doesn’t return a value, the return type should be void. Here are some examples of methods with different return types:

public class MyClass {
    public int add(int a, int b) {
        return a + b;
    }

    public boolean isPositive(int num) {
        return num > 0;
    }

    public void printName(String name) {
        System.out.println("Name: " + name);
    }
}

Methods with a return type of void are used when the method doesn’t need to return any value.

4. Java Method Calling

To call a method in Java, we need to specify the name of the method and any required parameters. Here are some examples of method calls with different parameter values:

public class Main {
    public static void main(String[] args) {
        printHello();

        int sum = add(2, 3);

        boolean result = isPositive(-5);
    }

    public static void printHello() {
        System.out.println("Hello");
    }

    public static int add(int a, int b) {
        return a + b;
    }

    public static boolean isPositive(int num) {
        return num > 0;
    }
}

5. Java Standard Library Method

Besides user-defined methods, Java also provides many standard library methods that can perform common tasks. These methods are part of the Java API and can be used by any Java program.

String str = "hello";
int len = str.length();

The length() method is a standard method of the String class that returns the length of a string.

6. Advantages of using methods

Using methods in Java programming has several advantages, including:

• Code Reuse: Methods allow programmers to reuse code, which can save time and effort.
• Readability: Breaking down a large program into smaller methods can make the code more readable and easier to understand.
• Modular programming: Methods promote modular programming, which is a software design technique that emphasizes the separation of functionality into independent, interchangeable modules.

Summary

In conclusion, Java methods are an essential feature of the Java programming language. They allow programmers to break down a large program into smaller, more manageable pieces, which promotes code reuse, readability, and modular programming. By understanding how to declare and use methods in Java, programmers can write more efficient, maintainable, and scalable code.

It is highly recommended that readers practice writing and using methods in their Java programs to gain proficiency in this fundamental aspect of Java programming. As always, the source code for this article is available on the GitHub repository.