Java Methods Overview

Why use methods?

• Can simplify code and make it easier to read.
• Encourages reuse of code and reduces repetition.
• Makes code more modular and easier to change.

Methods in Java

• A method is a block of code that performs a specific task.
• Defined using the following template:

public static returnType name(dataType parameter) {
  // body of method
} 

• Can have a return type, which dictates the data type of the value returned from the method.
• The void keyword is used when a method does not return a value.

Components of a method

• public: keyword indicating the method can be accessed from anywhere.
• static: keyword indicating the method is associated with the class, not an instance of the class.
• returnType: specifies the data type of the value returned by the method.
• name: the name of the method (use camelCase for naming).
• parameter(s): variables that are passed to the method when it is called.

How to call a method

• Methods can only be called after they have been defined within the class.
• The order of parameters in the method definition must match the arguments when calling the method.
• One method can call another if the called method is within the valid scope.

Example: isEven() method

• Takes an integer parameter num.
• Determines if the argument num is even or odd.
• Prints a result based on the parity of the input.
• Returns true if the number is even, false otherwise.
• Example:

public static Boolean isEven(int num) {
 if (num % 2 == 0) {
   System.out.println(num + " is even.");
   return true;
 } else {
   System.out.println(num + " is odd.");
   return false;
 }
}

Palindrome problem

• A palindrome is a word that reads the same forwards and backwards.
• Implement a Java method that:
  • Takes a word as input.
  • Determines if the word is a palindrome.
  • Return true if it is a palindrome, false if not.