Help! Base apparel coming soon.

I've done it by simply making a function which takes email as a parameter and called it in on click of a button to check if the entered email is correctly written if not it displays an error message.

I've checked your code it looks a bit complicated to be honest, you can just make it a function, make a variable with email regex and check in the function if the entered email matches the format and if not display the error message.

It might be a little outdated solution but it'll get you started and you can work on it from there.

Well done!

About your undefined problem, in JavaScript is not always very clear what is this when you are using a method. In your case, the this in this.iconError is the input element, which is the target of the event listener.

Try changing this line:

this.DOMInput.addEventListener(eventType, this.verify);

for:

this.DOMInput.addEventListener(eventType, () => this.verify());