Methods : Basics (Part 1)
Java Methods
⏺ A method is a block of code which only runs when it is called.
⏺ Methods are used to perform certain actions, which are also known as functions.
➤Why use methods?
To reuse code: define the code once, and use it many times.
➤Declaring a method
⏺ A method must be declared within a class.
⏺ It is defined with the name of the method, followed by parentheses () .
⏺ Method is created by first specifying its dataType such as void , int , string , etc.
and then its name.
⏺ When method is called :
void will not return any value
int will return an integer
String will return a string
➤Syntax:-
dataType
MethodName
() {
//block of code to be executed
}
For example I created a method named start ( ) which will print out starting machine when called.
🔔 static keyword is used when a method is declared and called in same class without instantiating i.e creating objects of it.static void
start
() { System.out.println("
Machine Starting
"); }
➤Calling a Method
⏺ To call a method in Java, write the method's name followed by two parentheses ( ) and a semicolon;
⏺ In the following example, start()
is used to print a text (the action), when it is called:
class
MyClass
{ static void
start
() { System.out.println("
Machine Starting
."); } public static void main(String[] args) {
//calling the start() method
start
(); } }
Output:-
Machine Starting.
⏺ A method can also be called multiple times.
class
MyClass
{ static void
start
() { System.out.println("
Machine Starting.
"); } public static void main(String[] args) {
//calling the start() method
start
();
start
();
sta
rt
(); } }
Output:-
Machine Starting.
Machine Starting.
Machine Starting.
More concepts of methods will be explained in the following tutorials.