What’s wrong with this code JavaScript

Question

There is a practice question in SoloLearn that I am not sure what’s wrong with the coding. I have written 2 lines of coding , see follows:

Question:

The program you are given should calculate the annual income of a given loan.
The program takes the loan initial amount and the annual interest percentage as input, then creates the loan object.
Complete the function outside the constructor to calculate the annual income, then assign that value to the corresponding field, that you also create, of the constructor in order to execute the given output.

Sample Input
15000
20

Sample Output
3000

Coding:

function main() {
//get the initial amount and the interest percentage
var amount = parseInt(readLine(),10);
var yearPercent = parseInt(readLine(),10);

var loan1 = new Loan(amount, yearPercent);

//output to console
console.log(loan1.yearIncome());
}

function Loan(amount, percent) {
this.amount = amount;
this.yearPercent = percent;
//my code is here 1
this.yearIncome = calcYearIncome
};

function calcYearIncome(amount,percent){
//my coding is here 2 complete the function to calculate yearly income
this.yearIncome= amount*percent/100;
}

Answer 1

try this.

function Loan(amount, percent) {
this.amount = amount;
this.yearPercent = percent;
//my code is here 1
this.yearIncome = calcYearIncome (amount,percent);
};

console.log(loan1.yearIncome());

then change the output to this
console.log(loan1.yearIncome);

change also this
function calcYearIncome(amount,percent){
//my coding is here 2 complete the function to calculate yearly income
this.yearIncome= amount*percent/100;
}

to this
function calcYearIncome(amount,percent){
//my coding is here 2 complete the function to calculate yearly income
return( amount*percent/100);
}

Answer 2

function main() {
//get the initial amount and the interest percentage
var amount = parseInt(readLine(),10);
var yearPercent = parseInt(readLine(),10);

var loan1 = new Loan(amount, yearPercent);

//output to console
console.log(loan1.yearIncome());
}

function Loan(amount, percent) {
this.amount = amount;
this.yearPercent = percent;
this.yearIncome = calcYearIncome;//your code goes here
}

function calcYearIncome(){
return this.amount * (this.yearPercent/100); //complete the function to calculate yearly income
}

Answer 3

It is working for me, btw why have you used readLine() ? I've used prompt in this example, and it works, you used loan.yearIncome() but it is not a function, remove the (). This works:

function main() {
var amount = parseInt(prompt(),10);
var yearPercent = parseInt(prompt(),10);
var loan1 = new Loan(amount, yearPercent);
console.log(loan1.yearIncome);
}

function Loan(amount, percent) {
this.amount = amount
this.yearPercent = percent
this.yearIncome = calcYearIncome(amount, percent)
};

function calcYearIncome(amount,percent){
return amount*percent/100
}

main()

Answer 4

You should call the function by writing () after calcYearIncome inside Loan and pass amount and percent to calcYearIncome(), coz qs says that assign the value of calcYearSome to this.yearIncome.

And yeah, return the value inside calcYearIncome function so that you can assign it to the property yearIncome

Fixed:
function Loan(amount, percent) {
this.amount = amount
this.yearPercent = percent
this.yearIncome = calcYearIncome(amount, percent)
};

function calcYearIncome(amount,percent){
return amount*percent/100
}

Answer 5

maf that is node js ,prompt won't work there ,tho I have no idea what is readLine and main function in node but I am assuming it's something how node process(or maybe sololearn did some changes) input from readLine function ,it calls main on its own and provides input to test

Answer 6

thanks but the suggested coding doesnt work

Answer 7

readLine() is provided as part of the solution by the program

Answer 8

Abhay yeah i figured that out, i have never done js challenges on sololearn that's why never encountered readLine(). But now it must work Cheri Yan just change it back to readLine() and see if it works. I tried fixing the code on my mobile on spck editor thats why changed it to prompt.

Answer 9

Hi there.

From what I understand, you are omitting the ; in the initialization of the this.yearIncome property and not utilising the “this” keyword when describing variables within the calcYearIncome function.

Here is the code that worked for me:

function Loan(amount, percent) {
this.amount = amount;
this.yearPercent = percent;
//your code goes here
this.yearIncome = calcYearIncome;

};

function calcYearIncome(amount,percent){
//complete the function to calculate yearly income
return (this.yearPercent / 100 ) * this.amount;
}

Answer 10

HI ! this is I think the neater way, to solve this problem

function main() {
//get the initial amount and the interest percentage
var amount = parseInt(readLine(),10);
var yearPercent = parseInt(readLine(),10);

var loan1 = new Loan(amount, yearPercent);

//output to console
console.log(loan1.yearIncome());
}

function Loan(amount, percent) {
this.amount = amount;
this.yearPercent = percent;
//your code goes here
this.yearIncome = calcYearIncome;

//the calcYearIncome function is store into yearIncome
};

function calcYearIncome(){
//complete the function to calculate yearly income
return (this.yearPercent/100)*this.amount

}

Answer 11

i also tried changing it to “prompt” but it doesnt work when i submitted to sololearn

Answer 12

it works now! really appreciate your help. thanks a lot !

Answer 13

Rana Pratap Singh

Answer 14

Welcomed always.

Answer 15

function main() {
//get the initial amount and the interest percentage
var amount = parseInt(readLine(),10);
var yearPercent = parseInt(readLine(),10);

var loan1 = new Loan(amount, yearPercent);

//output to console
console.log(loan1.yearIncome());
}

function Loan(amount, percent) {
this.amount = amount;
this.yearPercent = percent;
//your code goes here
this.yearIncome=calcYearIncome;

};

function calcYearIncome(){
//complete the function to calculate yearly income

return ((this.amount)*(this.yearPercent/100));

}

Answer 16

I find I just can't follow the logic. I don't want to copy out a correct answer, if possible I want to understand how it works, but this section of the course moves very fast for me. Anyone got any other good resources for this? Thanks

Answer 17

Owain, I hear you. Too fast for me too. I'd like to understand the Function, Object and Method concepts better. Even if I solve the problem sections I may not fully comprehend the concepts...

I understand Manish's logic though – except for this:
In his Loan function Manish already stores/defines
this.amount = amount;
this.yearPercent = percent;

What's the point though if he then needs to use this.amount and this.yearPercent for the return trigger again?
Why can't we use the parameters we stored above, as in:
return ((amount)*(percent/100));
or even
return (amount*percent)/100;

Anyone?!
Thanks!

Answer 18

function main() {
//get the initial amount and the interest percentage
var amount = parseInt(readLine(),10);
var yearPercent = parseInt(readLine(),10);

var loan1 = new Loan(amount, yearPercent);

//output to console
console.log(loan1.yearIncome());
}

function Loan(amount, percent) {
this.amount = amount;
this.yearPercent = percent;
this.yearIncome = calcYearIncome;//your code goes here
}

function calcYearIncome(){
return this.amount * (this.yearPercent/100); //complete the function to calculate yearly income
}

Good Luck