Javascript objects and method

Question

Please help! i just started learning objects ecc.. i didn't want to go ahead, because i wanted to really understand the Objects on javascript. So i tried to write some codes of an objects with hourly pay,weekly hours,expenses,overtime and 3 functions.

var monthlyPay = {
//hours per week
     hourWeek: 40,
//pay per hours
     hourlyPay: 10,
//all the monthly expenses
     mothlyExpenses: 120,
//additional hours of work
     overtime: 7,

//function that calculates the bonus based on the overtime and hourlyPay plus 4
     calculateBonus: function(){
     this.Bonus = this.overtime * (this.hourlyPay + 4);
 },
//function that calculates the total monthly pay
     calculatePay: function(){
     this.Pay = this.hourWeek * this.hourlyPay + this.Bonus;
 },
//function that calcutes the remaining money
     calculateMoney: function(){
     this.Money = this.monthlyExpenses - this.Pay;
 },

};
monthlyPay.calculateMoney();
monthlyPay.calculateBonus();
monthlyPay.calculatePay();
console.log(monthlyPay);

It runs with no error, but when i look at the browser console the Money property has a value of NaN. Thanks in advance for answering!!

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Well `Money` depends on the `Pay` value so you have to calculate that first. — Bergi, Nov 26 '17 at 15:12
The `this.Pay;` is not defined anywhere. So it would be `NaN`. — Praveen Kumar Purushothaman, Nov 26 '17 at 15:13
This reading could help a little : https://stackoverflow.com/a/47441358/1636522. — , Nov 26 '17 at 15:15
You have a spelling mistake, you wrote mothlyExpenses instead of monthlyExpenses — Patrick Hund, Nov 26 '17 at 15:15
Thanks to all of you!!! I really forgot about the orders that does matter when calling the function. — CLINToris2, Nov 26 '17 at 15:28

Sam Ho · Answer 1 · 2017-11-26T15:57:18.353

There are two bugs in your code.
The first one is mentioned by Barden.
Pay is called before its declaration which is undefeined.

Also you mis-spell monthlyExpenses for your variable declaration.
Therefore: a calculation of two undefined value is also undefined.

Try to debug with printing values which may be used for Money:

calculateMoney: function(){
    console.log(`Params : \nmonthlyExpenses: ${this.monthlyExpenses} \nPay: ${this.Pay}`);
    this.Money = this.mothlyExpenses - this.Pay;
}

Result is :
Params : 
monthlyExpenses: undefined
Pay: undefined

To summarise:
1. change the function call orders
2. make monthlyExpenses or mothlyExpenses spell the same

:)

score -1 · Answer 2 · answered Nov 26 '17 at 15:20

-1

summarizing what was said:

The order should be

monthlyPay.calculateBonus();
monthlyPay.calculatePay();
monthlyPay.calculateMoney();
console.log(monthlyPay);

And you should write

monthlyExpenses: 120,

answered Nov 26 '17 at 15:20

Barden

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Javascript objects and method

2 Answers2