In-class practice problem

iInheritance in ES5 through prototype

/**
 * Account class (Parent class)
 * @constructor
 */
var Account  = function() {
    this.amount = 0;

    this.setAmount = function(amount) {
        this.amount = amount;
    }

    this.getAmount = function() {
        return this.amount;
    }
}; 

/**
 * CheckingAccount class (First child class)
 * @constructor
 * @param {int} amount - The initial amount when you open the checking account
 */
var CheckingAccount = function(amount) {
    this.setAmount(amount);

    this.withdraw = function(amount) {
        var updatedAmount = this.getAmount() - amount;
        if (updatedAmount < 0) {
            throw new Error("Amount can't be negetive");
        }

        this.setAmount(updatedAmount);
        return this.getAmount();
    }

    this.deposit = function(amount) {
        this.setAmount(amount); 
    }
}

//inheritance 
CheckingAccount.prototype = new Account();


/**
 * SavingAccount class (Second child class)
 * @constructor
 * @param {int} amount - The initial amount when you open the saving account
 */
var SavingAccount = function(amount) {
    this.setAmount(amount);

    this.withdraw= function(amount) {
        var updatedAmount = this.getAmount() - amount;
        
        if (updatedAmount < 0) {
            throw new Error("Amount can't be negetive");
        } else if(updatedAmount < 500) {
            throw new Error("Amount can't be less than 500");
            
        }

        this.setAmount(updatedAmount);
        return this.getAmount();
    }

    this.deposit = function(amount) {
        this.setAmount(amount); 
    }
}


//inheritance 
SavingAccount.prototype = new Account();



//Test Case -- 1

var checkingAccont1 = new CheckingAccount(1000);
console.log("Balance: ", checkingAccont1.getAmount());

//Withdraw 100 
checkingAccont1.withdraw(100);

try{
    //Withdraw balance more than available balance
    checkingAccont1.withdraw(10000);
} catch (e) {
    console.log('error catched for negetive balance');
    console.log('everything is okay for checking');

}

//Test Case -- 2

var savingAccont1 = new SavingAccount(1000);
console.log("Balance: ", savingAccont1.getAmount());

//Withdraw 100 
savingAccont1.withdraw(100);

try{
    //Withdraw balance more than available balance
    savingAccont1.withdraw(500);
} catch (e) {
    console.log('error catched for less than 500');
    console.log('everything is okay for saving account');
}