Today I Learn JWT

Author: cod0216

.DS_Store

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+public class CommentJava {
+
+    public static void main(String[] args) {
+        System.out.println("hello java1"); //hello java1을 출력합니다.
+        //System.out.println("hello java2");
+
+        /*
+        System.out.println("hello java3");
+        System.out.println("hello java4");
+        */
+    }
+}

JAVA/.DS_Store

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+public class HelloJava {
+    public static void main(String[] args) {
+        System.out.println("hello java");
+    }
+}

JAVA/HelloDoc/.DS_Store

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+public class HelloJava2 {
+
+    public static void main(String[] args) {
+        System.out.println("hello java1");
+        System.out.println("hello java2");
+        System.out.println("hello java3");
+    }
+}

JAVA/src/CommentJava.java

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+// Press Shift twice to open the Search Everywhere dialog and type `show whitespaces`,
+// then press Enter. You can now see whitespace characters in your code.
+public class Main {
+    public static void main(String[] args) {
+        // Press Opt+Enter with your caret at the highlighted text to see how
+        // IntelliJ IDEA suggests fixing it.
+        System.out.printf("Hello and welcome!");
+
+        // Press Ctrl+R or click the green arrow button in the gutter to run the code.
+        for (int i = 1; i <= 5; i++) {
+
+            // Press Ctrl+D to start debugging your code. We have set one breakpoint
+            // for you, but you can always add more by pressing Cmd+F8.
+            System.out.println("i = " + i);
+        }
+    }
+}

JAVA/src/HelloJava.java

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+package array;
+
+public class Array1 {
+
+    public static void main(String[] args) {
+        int student1 = 90;
+        int student2 = 80;
+        int student3 = 70;
+        int student4 = 60;
+        int student5 = 50;
+
+        System.out.println("학생1 점수: " + student1);
+        System.out.println("학생2 점수: " + student2);
+        System.out.println("학생3 점수: " + student3);
+        System.out.println("학생4 점수: " + student4);
+        System.out.println("학생5 점수: " + student5);
+    }
+}

JAVA/src/HelloJava2.java

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+package array;
+
+public class Array1Ref1 {
+
+    public static void main(String[] args) {
+        int[] students; //배열 변수 선언
+        students = new int[5]; //배열 생성
+
+        //변수 값 대입
+        students[0] = 90;
+        students[1] = 80;
+        students[2] = 70;
+        students[3] = 60;
+        students[4] = 50;
+
+        //변수 값 사용
+        System.out.println("학생1 점수: " + students[0]);
+        System.out.println("학생2 점수: " + students[1]);
+        System.out.println("학생3 점수: " + students[2]);
+        System.out.println("학생4 점수: " + students[3]);
+        System.out.println("학생5 점수: " + students[4]);
+    }
+}

JAVA/src/Main.java

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+package array;
+
+public class Array1Ref2 {
+
+    public static void main(String[] args) {
+        int[] students; //배열 변수 선언
+        students = new int[5]; //배열 생성
+
+        //변수 값 대입
+        students[0] = 90;
+        students[1] = 80;
+        students[2] = 70;
+        students[3] = 60;
+        students[4] = 50;
+
+        //변수 값 사용
+        for (int i = 0; i < students.length; i++) {
+            System.out.println("학생" + (i + 1) + " 점수: " + students[i]);
+        }
+    }
+}

JAVA/src/array/Array1.java

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+package array;
+
+public class Array1Ref3 {
+
+    public static void main(String[] args) {
+        int[] students; //배열 변수 선언
+        students = new int[]{90, 80, 70, 60, 50}; //배열 생성과 초기화
+
+        //변수 값 사용
+        for (int i = 0; i < students.length; i++) {
+            System.out.println("학생" + (i + 1) + " 점수: " + students[i]);
+        }
+    }
+}

JAVA/src/array/Array1Ref1.java

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+package array;
+
+public class Array1Ref4 {
+
+    public static void main(String[] args) {
+        int[] students = {90, 80, 70, 60, 50};
+
+        //변수 값 사용
+        for (int i = 0; i < students.length; i++) {
+            System.out.println("학생" + (i + 1) + " 점수: " + students[i]);
+        }
+    }
+}

JAVA/src/array/Array1Ref2.java

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+package array;
+
+public class ArrayDi0 {
+
+    public static void main(String[] args) {
+        // 2x3 2차원 배열을 만든다.
+        int[][] arr = new int[2][3]; //행2, 열3
+
+        arr[0][0] = 1; //0행, 0열
+        arr[0][1] = 2; //0행, 1열
+        arr[0][2] = 3; //0행, 2열
+        arr[1][0] = 4; //1행, 0열
+        arr[1][1] = 5; //1행, 1열
+        arr[1][2] = 6; //0행, 2열
+
+        //0행 출력
+        System.out.print(arr[0][0] + " "); //0열 출력
+        System.out.print(arr[0][1] + " "); //1열 출력
+        System.out.print(arr[0][2] + " "); //2열 출력
+        System.out.println();//한 행이 끝나면 라인을 변경한다.
+
+        //1행 출력
+        System.out.print(arr[1][0] + " "); //0열 출력
+        System.out.print(arr[1][1] + " "); //1열 출력
+        System.out.print(arr[1][2] + " "); //2열 출력
+        System.out.println();//한 행이 끝나면 라인을 변경한다.
+    }
+}

JAVA/src/array/Array1Ref3.java

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+package array;
+
+public class ArrayDi1 {
+
+    public static void main(String[] args) {
+        // 2x3 2차원 배열을 만든다.
+        int[][] arr = new int[2][3]; //행2, 열3
+
+        arr[0][0] = 1; //0행, 0열
+        arr[0][1] = 2; //0행, 1열
+        arr[0][2] = 3; //0행, 2열
+        arr[1][0] = 4; //1행, 0열
+        arr[1][1] = 5; //1행, 1열
+        arr[1][2] = 6; //0행, 2열
+
+        for (int row = 0; row < 2; row++) {
+            System.out.print(arr[row][0] + " "); //0열 출력
+            System.out.print(arr[row][1] + " "); //1열 출력
+            System.out.print(arr[row][2] + " "); //2열 출력
+            System.out.println();//한 행이 끝나면 라인을 변경한다.
+        }
+    }
+}

JAVA/src/array/Array1Ref4.java

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+package array;
+
+public class ArrayDi2 {
+
+    public static void main(String[] args) {
+        // 2x3 2차원 배열을 만든다.
+        int[][] arr = new int[2][3]; //행2, 열3
+
+        arr[0][0] = 1; //0행, 0열
+        arr[0][1] = 2; //0행, 1열
+        arr[0][2] = 3; //0행, 2열
+        arr[1][0] = 4; //1행, 0열
+        arr[1][1] = 5; //1행, 1열
+        arr[1][2] = 6; //0행, 2열
+
+        for (int row = 0; row < 2; row++) {
+            for (int column = 0; column < 3; column++) {
+                System.out.print(arr[row][column] + " ");
+            }
+            System.out.println();//한 행이 끝나면 라인을 변경한다.
+        }
+    }
+}

JAVA/src/array/ArrayDi0.java

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+package array;
+
+public class ArrayDi3 {
+
+    public static void main(String[] args) {
+        // 2x3 2차원 배열을 만든다.
+        int[][] arr = {
+            {1,2,3},
+            {4,5,6}
+        }; //행2, 열3
+
+        for (int row = 0; row < arr.length; row++) {
+            for (int column = 0; column < arr[row].length; column++) {
+                System.out.print(arr[row][column] + " ");
+            }
+            System.out.println();//한 행이 끝나면 라인을 변경한다.
+        }
+    }
+}

JAVA/src/array/ArrayDi1.java

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+package array;
+
+public class ArrayDi4 {
+
+    public static void main(String[] args) {
+        // 2x3 2차원 배열을 만든다.
+        int[][] arr = new int[10][10];
+
+        int i = 1;
+        for (int row = 0; row < arr.length; row++) {
+            for (int column = 0; column < arr[row].length; column++) {
+                arr[row][column] = i++;
+            }
+        }
+
+        for (int row = 0; row < arr.length; row++) {
+            for (int column = 0; column < arr[row].length; column++) {
+                System.out.print(arr[row][column] + " ");
+            }
+            System.out.println();//한 행이 끝나면 라인을 변경한다.
+        }
+    }
+}

JAVA/src/array/ArrayDi2.java

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+package array;
+
+public class EnhancedFor1 {
+
+    public static void main(String[] args) {
+        int[] numbers = {1, 2, 3, 4, 5};
+
+        //일반 for문
+        for (int i = 0; i < numbers.length; i++) {
+            int number = numbers[i];
+            System.out.println(number);
+        }
+
+        //향상된 for문, for-each문
+        for (int number : numbers) {
+            System.out.println(number);
+        }
+
+        //for-each문을 사용할 수 없는 경우, 증가하는 index 값 필요
+        for (int i = 0; i < numbers.length; i++) {
+            System.out.println("number" + i + "번의 결과는: " + numbers[i]);
+        }
+
+    }
+}

JAVA/src/array/ArrayDi3.java

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+package array.ex;
+
+public class ArrayEx1 {
+    public static void main(String[] args) {
+        int student1 = 90;
+        int student2 = 80;
+        int student3 = 70;
+        int student4 = 60;
+        int student5 = 50;
+
+        int total = student1 + student2 + student3 + student4 + student5;
+        double average = (double) total / 5;
+
+        System.out.println("점수 총합: " + total);
+        System.out.println("점수 평균: " + average);
+    }
+}

JAVA/src/array/ArrayDi4.java

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+package array.ex;
+
+public class ArrayEx1Ref {
+    public static void main(String[] args) {
+        int[] students = {90, 80, 70, 60, 50};
+
+        int total = 0;
+        for (int i = 0; i < students.length; i++) {
+            total += students[i];
+        }
+        double average = (double) total / 5;
+        System.out.println("점수 총합: " + total);
+        System.out.println("점수 평균: " + average);
+    }
+}

JAVA/src/array/EnhancedFor1.java

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+package array.ex;
+
+import java.util.Scanner;
+
+public class ArrayEx2 {
+
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+        int[] numbers = new int[5];
+
+        System.out.println("5개의 정수를 입력하세요:");
+        for (int i = 0; i < numbers.length; i++) {
+            numbers[i] = scanner.nextInt();
+        }
+
+        System.out.println("출력");
+        for (int i = 0; i < numbers.length; i++) {
+            System.out.print(numbers[i]);
+            if (i < numbers.length - 1) {
+                System.out.print(", ");
+            }
+        }
+    }
+}

JAVA/src/array/ex/ArrayEx1.java

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+package array.ex;
+
+import java.util.Scanner;
+
+public class ArrayEx3 {
+
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+        int[] numbers = new int[5];
+
+        System.out.println("5개의 정수를 입력하세요:");
+        for (int i = 0; i < numbers.length; i++) {
+            numbers[i] = scanner.nextInt();
+        }
+
+        System.out.println("출력");
+        //0,1,2,3,4
+        for (int i = 4; i >= 0; i--) {
+            System.out.print(numbers[i]);
+            if (i > 0) {
+                System.out.print(", ");
+            }
+        }
+    }
+}

JAVA/src/array/ex/ArrayEx1Ref.java

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+package array.ex;
+
+import java.util.Scanner;
+
+public class ArrayEx4 {
+
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+        int[] numbers = new int[5];
+        int sum = 0;
+        double average;
+
+        System.out.println("5개의 정수를 입력하세요:");
+        for (int i = 0; i < 5; i++) {
+            numbers[i] = scanner.nextInt();
+            sum += numbers[i];
+        }
+
+        average = (double) sum / 5;
+        System.out.println("입력한 정수의 합계: " + sum);
+        System.out.println("입력한 정수의 평균: " + average);
+    }
+}