Java methods are blocks of code that are only executed when the specific method is called. Methods are extremely useful tools to reuse code or break down a large task into smaller chunks. Methods can accept a few parameters and return an object as well.

There are two types of methods:

1. User-defined Methods: methods we can to perform specific tasks

2. Standard Library Methods: methods included in Java libraries

User-Defined Methods

accessModifier returnType methodName() {
   // method content
}

accessModifier: the access type of the method, generally public or private

returnType: defines the type of the value that the method will return

methodName: the name of the method, which should be descriptive of the task or operation that the method is performing

method content: the content and operations included within the method

Standard Library Methods

Standard library methods are built-in and they are embedded within the Java class.

A few examples:

print()     // from java.io.PrintStream
sqrt()      // from the Math class

Example Program Using Methods

public class Calculator {
   public static int doubleIt(int num) {
      return num * 2;
   }
}

public class MyConsole {
   public static void main(String[] args) {
      // initialize a variable, and then print the variable doubled
      int value = 4;
      int doubledValue = Calculator.doubleIt(value);
      System.out.println("The double of " + value + " is " + doubledValue + ".");
   }
}