updated the solutions

Author: pray3m

LAB2/booleanTest.java

@@ -7,8 +7,6 @@ public static void main(String[] args){
         System.out.println("b is "+ b);
         System.out.println("b is " + !b);
 
-       // TODO :Complete the Program
-
         if(b) System.out.println("This is executed.");
         b=false;
         if(b) System.out.println("This is not executed.");

LAB4/InheritanceDemo.java

@@ -0,0 +1,64 @@
+/*5. Create a class student with instance variables roll_no and two methods to read and display the
+roll_no. Then create another class Test that inherits class student, consisting of its own instance
+variables to hold the marks of two subjects and also methods to read and display the marks.
+Finally, create another class Result which inherits class Test. It also has its own instance variable
+total to hold the total of two marks scored by the student. Similarly, it has methods to calculate
+and display the total. Create some instance of above classes and demonstrate inheritance. */
+
+/*
+ * author: @pray3m
+ */
+
+class Student{
+    int rollNo;
+    Student(int rollNo){
+        this.rollNo=rollNo;
+    }
+
+    void display(){
+        System.out.println("Roll No: "+rollNo);
+    }
+}
+
+class Test extends Student{
+    int marks1,marks2;
+
+    Test(int roll,int marks1,int marks2){
+        super(roll);
+        this.marks1=marks1;
+        this.marks2=marks2;
+    }
+
+    void displayMarks(){
+        System.out.printf("The marks \n\t Sub 1 :%d \n\t Sub 2 : %d",marks1,marks2);
+    }
+}
+
+class Result extends Test{
+    int total=0;
+
+    Result(int roll,int marks1, int marks2){
+        super(roll, marks1, marks2);
+        total=marks1+marks2;
+    }
+
+    int calcTotal(){
+        return total;
+    }
+
+    void displayResult(){
+        super.display();
+        super.displayMarks();
+        System.out.println("\n The total marks is: "+total);
+    }
+}
+
+
+public class InheritanceDemo{
+    public static void main(String[] args) {
+        Result s1=new Result(1,56,76);
+        s1.displayResult();
+    }
+}
+
+

LAB4/README.md

@@ -12,7 +12,7 @@ super, abstract class and method.
  - [Q.N 2](https://github.com/pray3m/JavaPrograms/blob/main/LAB4/MultilevelInheritance.java)
  - [Q.N 3](https://github.com/pray3m/JavaPrograms/blob/main/LAB4/HierarchicalInheritance.java)
  - [Q.N 4*](https://github.com/pray3m/JavaPrograms/blob/main/LAB4/BoxDemo.java)
- - [Q.N 5*](https://github.com/pray3m/JavaPrograms/blob/main/LAB4/BoxDemo.java)
+ - [Q.N 5](https://github.com/pray3m/JavaPrograms/blob/main/LAB4/InheritanceDemo.java)
  - [Q.N 6](https://github.com/pray3m/JavaPrograms/blob/main/LAB4/SuperKey.java)
  - [Q.N 7](https://github.com/pray3m/JavaPrograms/blob/main/LAB4/superMethod.java)
  - [Q.N 8*](https://github.com/pray3m/JavaPrograms/blob/main/LAB4/BoxDemo.java)