Check it out on my Github repo :)
Below are a few things that I learned while building this calculator:
e.preventDefault()
I learned, the importance of e.preventDefault()
when you are in development and using javascript.
While building my calculator, I would input a number and the page would immediately refresh. I could not figure out why until I reviewed some of the notes I took in the past about e.preventDefault()
How I interpret the above is that JS has default settings for event listeners and e.preventDefault()
stops the default settings from from taken place unless it is called upon. I could be wrong, but all I know is that it stopped my page from constantly refreshing when I needed to handle my click event.
Changing Inputted Value from String to Integer
I also learned an easy way to convert a string to an integer:
let checkAmount = document.getElementById('check-amount').value;
Above document.getElementById('check-amount').value
returns a string value that the user inputs. However, I was building a tip calculator meaning I had to make calculations and I can not do that with a string. So to convert the value, I learned that all I had to do was put a +
in front of the value and it would convert it for me.
let checkAmount = +document.getElementById('check-amount').value;
isNaN function
Lastly, error catch! I learned how to use isNaN
function to stop check if a value is NaN or not.
if (isNaN(checkAmount)){
displayResults("Error, please enter a number");
return;
}
Song of the day: I have always been obsessed with brasstracks! Give them a listen π
Sincerely,
Brittany
Top comments (2)
Super inspiring series, thanks for sharing. It is better if you use Number.isNaN() instead of isNaN() otherwise there are cases where could be type coercion that throws an unexpected value.
This put a smile on my face! Thank you for reading ππ