# HackerRank Day 12 Inheritance 30 days of code solution

In this HackerRank Day 12 Inheritance 30 days of code problem set, we have two classes, Person and Student. where the Person is the base class and the Student is the derived class. we need to inherit all the data from Person class and use them in Student class.

## Problem solution in Python 2 programming.

```class Student(Person):
def __init__(self, firstName, lastName, idNumber, scores):
self.firstName = firstName
self.lastName = lastName
self.idNumber = idNumber
self.scores = map(int, scores)

def calculate(self):
avg = sum(self.scores) / len(self.scores)
if avg <= 100 and avg >= 90:
return 'O'
if avg <= 90 and avg >= 80:
return 'E'
if avg <= 80 and avg >= 70:
return 'A'
if avg <= 70 and avg >= 55:
return 'P'
if avg <= 55 and avg >= 40:
return 'D'
else:
return 'T'
```

## Problem solution in Python 3 programming.

```class Student(Person):
#   Class Constructor
#
#   Parameters:
#   firstName - A string denoting the Person's first name.
#   lastName - A string denoting the Person's last name.
#   id - An integer denoting the Person's ID number.
#   scores - An array of integers denoting the Person's test scores.
#

#   Function Name: calculate
#   Return: A character denoting the grade.
#

def __init__(self,firstName, lastName, idNum , scores):

self.firstName = firstName
self.lastName = lastName
self.idNum = idNum
self.scores = scores

def printPerson(self):
print("Name: " + lastName + ", " + firstName)
print("ID:", idNum)

def calculate(self):
x = len(scores)
n = 0
for i in range(x):
n+=scores[i]

y = int(n)//int(x)

if 90<= y <= 100:
return 'O'
elif 80<= y < 90:
return 'E'
elif 70<= y < 80:
return 'A'
elif 55<= y < 70:
return 'P'
elif 40<= y < 55:
return 'D'
else:
return 'T'

```

### Problem solution in java programming.

```class Student extends Person{
private int[] testScores;

Student(String firstName, String lastName, int identification, int[] scores){
super(firstName, lastName, identification);
this.testScores = scores;
}

public char calculate(){
int average = 0;
for(int i = 0; i < testScores.length; i++){
average += testScores[i];
}
average = average / testScores.length;

if(average >= 90){
return 'O'; // Outstanding
}
else if(average >= 80){
return 'E'; // Exceeds Expectations
}
else if(average >= 70){
return 'A'; // Acceptable
}
else if(average >= 55){
}
else if(average >= 40){
}
else{
return 'T'; // Troll
}
}
}```

### Problem solution in c++ programming.

```class Student : public Person{
private:
vector<int> testScores;

public:
Student(string firstName, string lastName, int id, vector<int> scores) : Person(firstName, lastName, id) {
this->testScores = scores;
}

// Write char calculate()
char calculate() {
int sumScore = 0;
for (int i = 0; i < testScores.size(); i++) {
sumScore += testScores[i];
}
int averageScore = sumScore / testScores.size();

if (averageScore <= 100 && averageScore >= 90) {
return 'O';
} else if (averageScore < 90 && averageScore >= 80) {
return 'E';
} else if (averageScore < 80 && averageScore >= 70) {
return 'A';
} else if (averageScore < 70 && averageScore >= 55) {
return 'P';
} else if (averageScore < 55 && averageScore >= 40) {
return 'D';
}
return 'T';
}
};```

### Problem solution in Javascript programming.

```class Student extends Person {
/*
*   Class Constructor
*
*   @param firstName - A string denoting the Person's first name.
*   @param lastName - A string denoting the Person's last name.
*   @param id - An integer denoting the Person's ID number.
*   @param scores - An array of integers denoting the Person's test scores.
*/
constructor(firstname, lastname, id, scores) {
super(firstname, lastname, id);
this.scores = scores;
}

/*
*   Method Name: calculate
*   @return A character denoting the grade.
*/
calculate() {
var sum = this.scores.reduce((acc, num) => {
acc += num;
return acc;
});
var avg = sum / this.scores.length;

if (avg >= 90) {
return "O";
}
else if (avg >= 80) {
return "E";
}
else if (avg >= 70) {
return "A";
}
else if (avg >= 55) {
return "P";
}
else if (avg >= 40) {
return "D";
}
else {
return "T";
}
}

}```

1. Using lengthy if else is not ideal.

`calculate() {
let sum = this.scores.reduce((acc, num) => {
acc += num;
return acc;
});
let avg = sum / this.scores.length,
grades = {'90':'O', '80':'E', '70': 'A', '55': 'P', '40': 'D'},