CODEWITHSUNDEEP
javascriptcalculator
Dan
Dan

Reputation: 91

JS issue then creating a calculator and being able to type in multiple numbers

I have been following a video tutorial for creating a calculator, I have not completed the program yet, but I should be able to type multiple numbers on the calculator then pressing the buttons (without any addition, subtraction, multiplication or division, yet) but instead I get error messages, which I'm not sure how to fix. Can anyone help?

Calculator link

Upvotes: 0

Views: 51

Answers (1)

Alex Brohshtut
Alex Brohshtut

Reputation: 2060

Dan, you should always have a look at the errors and try to figure out what's going on. Your error says: Uncaught TypeError: Cannot read property 'toString' of undefined Line: 22

Which means, 'hey, something that you try to call toString on is actually not something like an object or value, but it is undefined.

Now you should go to line 22, which is:

this.currentOperand = this.currentOperand.toString() + number.toString();

And try to figure out what is wrong - usually you use debugger for it, or just console.log, like this:

appendNumber(number) {
  console.log('Current operand: ', this.currentOperand);
  console.log('Number: ', number);

  this.currentOperand = this.currentOperand.toString() + number.toString();
}

In your case - this.currentOperand is undefined, since you never initialise it (it assigned in calculator.clear, but you never call it).

This fix will make you able to continue:

const calculator = new Calculator(previousOperandTextElement, currentOperandTextElement);
calculator.clear()

Upvotes: 4

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