Merge pull request #5467 from eugenp/bael-2123-modulo

Bael 2123 modulo

core-java-8/findItemsBasedOnValues/.gitignore

@@ -1 +0,0 @@
-/bin/

core-java-collections/src/test/java/com/baeldung/findItems/FindItemsBasedOnOtherStreamUnitTest.java

@@ -1,93 +1,89 @@
-package findItems;
+package com.baeldung.findItems;
-
+
-import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertEquals;
-
+
-import java.text.ParseException;
+import java.text.ParseException;
-import java.util.ArrayList;
+import java.util.ArrayList;
-import java.util.Collections;
+import java.util.Collections;
-import java.util.List;
+import java.util.List;
-import java.util.stream.Collectors;
+import java.util.stream.Collectors;
-
+
-import org.junit.Test;
+import org.junit.Test;
-
+
-public class FindItemsBasedOnValues {
+public class FindItemsBasedOnOtherStreamUnitTest {
-
+
-    List<Employee> EmplList = new ArrayList<Employee>();
+    private List<Employee> employeeList = new ArrayList<Employee>();
-    List<Department> deptList = new ArrayList<Department>();
+
-
+    private List<Department> departmentList = new ArrayList<Department>();
-    public static void main(String[] args) throws ParseException {
+
-        FindItemsBasedOnValues findItems = new FindItemsBasedOnValues();
+    @Test
-        findItems.givenDepartmentList_thenEmployeeListIsFilteredCorrectly();
+    public void givenDepartmentList_thenEmployeeListIsFilteredCorrectly() {
-    }
+        Integer expectedId = 1002;
-
+
-    @Test
+        populate(employeeList, departmentList);
-    public void givenDepartmentList_thenEmployeeListIsFilteredCorrectly() {
+
-        Integer expectedId = 1002;
+        List<Employee> filteredList = employeeList.stream()
-
+            .filter(empl -> departmentList.stream()
-        populate(EmplList, deptList);
+                .anyMatch(dept -> dept.getDepartment()
-
+                    .equals("sales") && empl.getEmployeeId()
-        List<Employee> filteredList = EmplList.stream()
+                    .equals(dept.getEmployeeId())))
-            .filter(empl -> deptList.stream()
+            .collect(Collectors.toList());
-                .anyMatch(dept -> dept.getDepartment()
+
-                    .equals("sales") && empl.getEmployeeId()
+        assertEquals(expectedId, filteredList.get(0)
-                    .equals(dept.getEmployeeId())))
+            .getEmployeeId());
-            .collect(Collectors.toList());
+    }
-
+
-        assertEquals(expectedId, filteredList.get(0)
+    private void populate(List<Employee> EmplList, List<Department> deptList) {
-            .getEmployeeId());
+        Employee employee1 = new Employee(1001, "empl1");
-    }
+        Employee employee2 = new Employee(1002, "empl2");
-
+        Employee employee3 = new Employee(1003, "empl3");
-    private void populate(List<Employee> EmplList, List<Department> deptList) {
+
-        Employee employee1 = new Employee(1001, "empl1");
+        Collections.addAll(EmplList, employee1, employee2, employee3);
-        Employee employee2 = new Employee(1002, "empl2");
+
-        Employee employee3 = new Employee(1003, "empl3");
+        Department department1 = new Department(1002, "sales");
-
+        Department department2 = new Department(1003, "marketing");
-        Collections.addAll(EmplList, employee1, employee2, employee3);
+        Department department3 = new Department(1004, "sales");
-
+
-        Department department1 = new Department(1002, "sales");
+        Collections.addAll(deptList, department1, department2, department3);
-        Department department2 = new Department(1003, "marketing");
+    }
-        Department department3 = new Department(1004, "sales");
+}
-
+
-        Collections.addAll(deptList, department1, department2, department3);
+class Employee {
-    }
+    private Integer employeeId;
-}
+    private String employeeName;
-
+
-class Employee {
+    Employee(Integer employeeId, String employeeName) {
-    Integer employeeId;
+        super();
-    String employeeName;
+        this.employeeId = employeeId;
-
+        this.employeeName = employeeName;
-    public Employee(Integer employeeId, String employeeName) {
+    }
-        super();
+
-        this.employeeId = employeeId;
+    Integer getEmployeeId() {
-        this.employeeName = employeeName;
+        return employeeId;
-    }
+    }
-
+
-    public Integer getEmployeeId() {
+    public String getEmployeeName() {
-        return employeeId;
+        return employeeName;
-    }
+    }
-
+
-    public String getEmployeeName() {
+}
-        return employeeName;
+
-    }
+class Department {
-
+    private Integer employeeId;
-}
+    private String department;
-
+
-class Department {
+    Department(Integer employeeId, String department) {
-    Integer employeeId;
+        super();
-    String department;
+        this.employeeId = employeeId;
-
+        this.department = department;
-    public Department(Integer employeeId, String department) {
+    }
-        super();
+
-        this.employeeId = employeeId;
+    Integer getEmployeeId() {
-        this.department = department;
+        return employeeId;
-    }
+    }
-
+
-    public Integer getEmployeeId() {
+    String getDepartment() {
-        return employeeId;
+        return department;
-    }
+    }
-
+
-    public String getDepartment() {
-        return department;
-    }
-
 }

core-java/src/test/java/com/baeldung/modulo/ModuloUnitTest.java

@@ -0,0 +1,54 @@
+package com.baeldung.modulo;
+
+import org.junit.Test;
+import static org.assertj.core.api.Java6Assertions.*;
+
+public class ModuloUnitTest {
+
+  @Test
+  public void whenIntegerDivision_thenLosesRemainder(){
+    assertThat(11 / 4).isEqualTo(2);
+  }
+
+  @Test
+  public void whenDoubleDivision_thenKeepsRemainder(){
+    assertThat(11 / 4.0).isEqualTo(2.75);
+  }
+
+  @Test
+  public void whenModulo_thenReturnsRemainder(){
+    assertThat(11 % 4).isEqualTo(3);
+  }
+
+  @Test(expected = ArithmeticException.class)
+  public void whenDivisionByZero_thenArithmeticException(){
+    double result = 1 / 0;
+  }
+
+  @Test(expected = ArithmeticException.class)
+  public void whenModuloByZero_thenArithmeticException(){
+    double result = 1 % 0;
+  }
+
+  @Test
+  public void whenDivisorIsOddAndModulusIs2_thenResultIs1(){
+    assertThat(3 % 2).isEqualTo(1);
+  }
+
+  @Test
+  public void whenDivisorIsEvenAndModulusIs2_thenResultIs0(){
+    assertThat(4 % 2).isEqualTo(0);
+  }
+
+  @Test
+  public void whenItemsIsAddedToCircularQueue_thenNoArrayIndexOutOfBounds(){
+    int QUEUE_CAPACITY= 10;
+    int[] circularQueue = new int[QUEUE_CAPACITY];
+    int itemsInserted = 0;
+    for (int value = 0; value < 1000; value++) {
+      int writeIndex = ++itemsInserted % QUEUE_CAPACITY;
+      circularQueue[writeIndex] = value;
+    }
+  }
+
+}