[Introduction to Java] How to write a Java program

I'm a fledgling programmer for the first year. This is a collection of personal notes that have been organized and published for review purposes. Please note that there is a high possibility that you are wrong.

Hello World!

public class Main{
    public static void main(String[] args){
        System.out.println("Hello World!");

--Just output the string "Hello World!". It is called "the most famous program in the world". ――At first, remember that you write it like this.

Basic structure of Java program

public class Main{
	public static void main(String[] args){
		//Write the process to be executed here

--The structure is that the class is on the outside and the method is on the inside. --Basically, write in order from the outside to the inside

How to write a comment

//Comment here

Comment here

--/ // is recognized as a comment and is not processed as a program -The part surrounded by / \ * and \ * / is also recognized as a comment (multiple lines are possible)

The contents of the method

Roughly speaking, the contents of the method are the following four.

  1. Statement declaring a variable
  2. Statement to calculate
  3. Statement that executes the instruction
  4. Control statements (if statements, for statements, etc.)
public void sample(){
	String message = "";
	int numberA = 1;
	int numberB = 3;
	int bumberC = 0;

	numberC = numberA + numberB; 
	//Control what to do
	if( numberC > 2 ){
		//Substitute (a type of calculation)
		message = "numberC is greater than 2";;
	//Execute the instruction

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