first commit

src/nestech/javacourse/example/baitap/Calculator.java

@@ -11,6 +11,44 @@
 public class Calculator {
     public static void main(String[] args) {
         Scanner scanner = new Scanner(System.in);
-        // implement your code here
+        boolean isRunning = true;
+
+        while(isRunning){
+            System.out.println("1. Summation (+) ");
+            System.out.println("2. Subtraction (-) ");
+            System.out.println("3. Multiplication (*)");
+            System.out.println("4. Division (/) ");
+            System.out.println("0. Exit");
+            int choice = scanner.nextInt();
+
+            if(choice != 0){
+                System.out.println("Enter first number: ");
+                double firstNumber = scanner.nextDouble();
+                System.out.println("Enter second number: ");
+                double secondNumber = scanner.nextDouble();
+
+                switch (choice){
+                    case 1:
+                        System.out.println(firstNumber + secondNumber);
+                        break;
+                    case 2:
+                        System.out.println(firstNumber - secondNumber);
+                        break;
+                    case 3:
+                        System.out.println(firstNumber * secondNumber);
+                        break;
+                    case 4:
+                        System.out.println(firstNumber / secondNumber);
+                        break;
+                    default:
+                        System.out.println("The choice is invalid please enter again");
+                }
+
+            }
+            else {
+                System.out.println("Closing application...");
+                isRunning = false;
+            }
+        }
     }
 }

src/nestech/javacourse/example/baitap/PrimeChecker.java

@@ -27,8 +27,17 @@ public static void main(String[] args) {
 
     public static boolean isPrime(int n) {
         boolean isValid = false;
-        // Implement your code here
-
+        if (n > 2){
+            for(int i = 2; i < Math.sqrt(n); i++){
+                if(n % i != 0){
+                    isValid = true;
+                    break;
+                }
+                else {
+                    isValid = false;
+                }
+            }
+        }
         return isValid;
     }
 }

src/nestech/javacourse/example/baitap/SecondLargestNumber.java

@@ -20,7 +20,20 @@ public static void main(String[] args) {
 
     public static int findSecondLargest(int[] arr) {
         int secondLargest = Integer.MIN_VALUE;
-        // Implement your code here
+        int largest = Integer.MIN_VALUE; // đảm bảo các giá trị của số nguyên trong mảng sẽ lớn hơn giá trị ban đầu
+
+        if(arr.length < 2){
+            return Integer.MIN_VALUE;
+        }
+
+        for (int num : arr){
+            if(num > largest){
+                secondLargest = largest;
+                largest = num;
+            }else if(num > secondLargest && num != largest){
+                secondLargest = num;
+            }
+        }
 
         return secondLargest;
     }

src/nestech/javacourse/example/baitap/StudentManagement.java

@@ -0,0 +1,20 @@
+package nestech.javacourse.example.baitap;
+
+
+import nestech.javacourse.example.condition.Student;
+
+public class StudentManagement {
+    public static void main(String[] args) {
+        Student[] stdArray = new Student[3];
+
+        stdArray[0] = new Student(1,"Nguyen","Le",9);
+        stdArray[1] = new Student(1,"Hieu","Nguyen",8);
+        stdArray[2] = new Student(1,"Ly","Pham",10);
+
+        for(Student score : stdArray){
+            if(score.getScore() > 5){
+                System.out.println(score.getFirstName());
+            }
+        }
+    }
+}

src/nestech/javacourse/example/baitap/SumDuplicateElementCalculator.java

@@ -18,7 +18,14 @@ public static void main(String[] args) {
 
     public static int calculateCommonElementsSum(int[] arr1, int[] arr2) {
         int sum = 0;
-        // Implement your code here
+        for(int i = 0; i < arr1.length; i++){
+            for( int j = 0; j < arr2.length; j++){
+                if(arr1[i] == arr2[j]){
+                    sum += arr1[i] + arr2[j];
+                    break;
+                }
+            }
+        }
         return sum;
     }
 

src/nestech/javacourse/example/baitap/exerciseswithfiles/Employee.java

@@ -0,0 +1,60 @@
+package nestech.javacourse.example.baitap.exerciseswithfiles;
+
+import java.io.Serializable;
+
+public class Employee implements Serializable {
+
+    private long id;
+    private String name;
+    private int age;
+    private String position;
+
+    public Employee(long id, String name, int age, String position) {
+        this.id = id;
+        this.name = name;
+        this.age = age;
+        this.position = position;
+    }
+
+    @Override
+    public String toString() {
+        return "Employee{" +
+                "id=" + id +
+                ", name='" + name + '\'' +
+                ", age='" + age + '\'' +
+                ", position='" + position + '\'' +
+                '}';
+    }
+
+    public long getId() {
+        return id;
+    }
+
+    public void setId(long id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public int getAge() {
+        return age;
+    }
+
+    public void setAge(int age) {
+        this.age = age;
+    }
+
+    public String getPosition() {
+        return position;
+    }
+
+    public void setPosition(String position) {
+        this.position = position;
+    }
+}