[Java] Introductory structure Class definition Relationship between class and instance Method definition format

Output

What is a class? Class = field + method A method defines a process.

package javabase; // ← Package declaration class Staff {// ← template String name; int staffid; String email; }

Definition of 1 class public class StaffInfo {// ← Class definition

public static void main (String [] args) {// Method definition

Staff yamada = new Staff (); // ← Instantiation yamada.name ="Taro Yamada";

	System.out.println(yamada.name);

}

}

Create Java program = Create class

2 Relationship between class and instance // Class = template Taiyaki mold // Instance = The part Taiyaki generated from the template is the instance. // class Staff {// ← Staff class (template) // String name; // int staffid; // String email; //} // Staff yamada = new Staff (); // Mr. Yamada's instance (actual)

3 Method definition format

//クラスとは

//クラスX

// Store data Field A.B // Description processing method XYZ

// public class StaffInfo {// ← Class definition Declaration that the class will be defined from now on

// public static void main (String [] args) {// Method definition Med definition used in this class

//メソッドの定義 //public←アクセス修飾子

// public accessible from other classes // protected In the same package / inherited class // None Same package only //private

//メソッドの定義 // static ← Other modifiers

// abstract abstract class method // static Can be called directly from the class (not called from the instance) // final cannot be changed

//void // void Return type

//処理結果を繰り返す＞返り値の型を定義

// Do not repeat the value> [void]

// main (String [] args) ← method name (argument) //メソッドを呼び出すときにパラメーターを渡す。 //パラメータ＝引数 //カンマで複数渡せる

2 // Relationship between class and instance // Class = template Taiyaki mold // Instance = The part Taiyaki generated from the template is the instance. // class Staff {// ← Staff class (template) // String name; // int staffid; // String email; //} // Staff yamada = new Staff (); // Instance of Mr. Yamada (actual)

// 3 Method definition format