혀가 길지 않은 개발자

Iterator + ArrayList import java.util.ArrayList; import java.util.Iterator; public class JavaTest { public static void main(String[] args) { ArrayList arrStr = new ArrayList(); arrStr.add("James Kim"); arrStr.add("Kevin Jang"); arrStr.add("Jason Park"); Iterator iterator = arrStr.iterator(); while (iterator.hasNext()) { System.out.println(iterator.next()); } } }

import java.util.HashSet; import java.util.Iterator; public class JavaTest { public static void main(String[] args) { HashSet set = new HashSet(); set.add(3); set.add(2); set.add(1); set.add(2); set.add(2); set.add(2); Iterator iterator = set.iterator(); while (iterator.hasNext()) { System.out.println(iterator.next()); } } } 중복되는 값은 허용하지 않음. 자동 정렬이 돼서 출력됨. 원래 TreeSet 이 자동 정렬되는데 HashSet 도 자동 정렬되네..

Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK activity_main.xml activity_sub.xml SubActivity.java package com.jwsoft.javaproject; import androidx.appcompat.app.AppCompatActivity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.Button; public class SubActivity extends AppCompatActivity { private Button btnSub; @Override p..

activity_main.xml MainActivity.java package com.jwsoft.javaproject; import androidx.appcompat.app.AppCompatActivity; import android.content.Context; import android.os.Bundle; import android.view.View; import android.view.inputmethod.InputMethodManager; import android.widget.Button; import android.widget.EditText; public class MainActivity extends AppCompatActivity { private Button btnShowKeyboar..

import java.util.Scanner; public class JavaTest { public static void main(String args[]) { Scanner scanner = new Scanner(System.in); String name = scanner.nextLine(); int age = Integer.parseInt(scanner.nextLine()); System.out.println("name: " + name); System.out.print("age: " + age); } } import java.util.Scanner; public class JavaTest { public static void main(String args[]) { Scanner scanner = ..