Hackerrank Day 4: Class vs. Instance 30 days of code solution

HackerRank Day 4 class vs instance solution – In this HackerRank Day 4 class vs Instance, 30 days of code problem Write a Person class with an instance variable, age, and a constructor that takes an integer, initialAge, as a parameter. The constructor must assign initialAge to age after confirming the argument passed as initialAge is not negative; if a negative argument is passed as initialAge, the constructor should set age to 0 and print Age is not valid, setting age to 0.

Objective
In this challenge, we’re going to learn about the difference between a class and an instance; because this is an Object Oriented concept, it’s only enabled in certain languages.

Task
Write a Person class with an instance variable, age, and a constructor that takes an integer, initialAge, as a parameter. The constructor must assign initialAge to age after confirming the argument passed as initialAge is not negative; if a negative argument is passed as initialAge, the constructor should set Age to 0 and print Age is not valid, setting age to 0.. In addition, you must write the following instance methods:

1. yearPasses() should increase the age instance variable by 1.
2. amIOld() should perform the following conditional actions:
   • If age < 13, print You are young..
   • If  age >= 13 and age < 18, print You are a teenager..
   • Otherwise, print You are old..

To help you learn by example and complete this challenge, much of the code is provided for you, but you’ll be writing everything in the future. The code that creates each instance of your Person class is in the main method. Don’t worry if you don’t understand it all quite yet!

Problem solution in Python 2 programming.

class Person:
    def __init__(self,initialAge):
        # Add some more code to run some checks on initialAge
        if initialAge < 0:
            self.age = 0
            print "Age is not valid, setting age to 0."
        else:
            self.age = initialAge
    def amIOld(self):
        # Do some computations in here and print out the correct statement to the console
        if self.age < 13:
            print "You are young."
        elif self.age < 18:
            print "You are a teenager."
        else:
            print "You are old."
    def yearPasses(self):
        # Increment the age of the person in here
        self.age += 1

Problem solution in Python 3 programming.

class Person:
    def __init__(self,initialAge):
        # Add some more code to run some checks on initialAge
        if initialAge < 0:
            self.age = 0
            print("Age is not valid, setting age to 0.")
        else:
            self.age = initialAge
    def amIOld(self):
        # Do some computations in here and print out the correct statement to the console
        if self.age < 13:
            print("You are young.")
        elif self.age>=13 and self.age <18:
            print("You are a teenager.")
        else:
            print("You are old.")
    def yearPasses(self):
        # Increment the age of the person in here
        self.age += 1

Problem solution in java programming.

public class Person {
    private int age;	
  
	public Person(int initialAge) {
  		if(initialAge < 0){
            age = 0;
            System.out.println("Age is not valid, setting age to 0.");
        }else{
            age = initialAge;
        }
	}

	public void amIOld() {
        String ans;
  		if(age < 13){
            ans = "You are young.";
        }else if(age >= 13 && age < 18){
            ans = "You are a teenager.";
        }else{
            ans = "You are old.";
        }
        System.out.println(ans);
	}

	public void yearPasses() {
  		age += 1;
	}

Problem solution in c++ programming.

class Person{
public:
   int age ;
   Person(int initialAge);
   void amIOld();
   void yearPasses();
};
Person::Person(int initialAge){
  if(initialAge==NULL || initialAge<0){
      age=0;
      cout<<"Age is not valid, setting age to 0.n";
  }else {
      age=initialAge;
  }
}
void Person::amIOld(){
    if(age<13){
        cout<<"You are young.n";
    } else if(age>=13 && age<18){
        cout<<"You are a teenager.n";
    } else{
        cout<<"You are old.n";
    }

}
    

void Person::yearPasses(){
  age+=1;

}

Problem solution in Javascript programming.

function Person(initialAge){
    // Add some more code to run some checks on initialAge
    if (initialAge > 0) this.age = initialAge;
    else {
        this.age = 0;
        console.log("Age is not valid, setting age to 0.");
    }
  this.amIOld=function(){
   // Do some computations in here and print out the correct statement to the console
      if (this.age < 13) console.log("You are young.");
      else if (this.age < 18) console.log("You are a teenager.");
      else console.log("You are old.");

  };
   this.yearPasses=function(){
          this.age++;
   };
}