Textbox initial and new values

[Plebian]

Good day everyone.

Quite new to Javascript, I have a small problem I cant seem to solve.
The idea is, when I press my “calculate” button, it will do calculations that I have set down in my function. The values are taken from input text box. The initial value is set to for example “4”, when I change the values in my text box, I want my function to keep using those new values which I have in my textbox. When hitting the calculate button, it will always use the new value.

this.calculate.addEventListener(“click”, calculations.bind(this)); //calculate button

function calculations(){
document.getElementById(“inputtextbox”).value = “4”; //input box, initial value 4
if (inputtextbox !== 4) {
var value = Number(document.getElementById(“inputtextbox”).value); //new values to be used
}
//using the “value” variable to do some maths down the line
}

Thank you for your time

[jsdisco]

@Plebian

this.calculate.addEventListener("click", calculations.bind(this));  //calculate button

function calculations(){
	document.getElementById("inputtextbox").value = "4";  //input box, initial value 4
	if (inputtextbox !== 4) {
		var value = Number(document.getElementById("inputtextbox").value);    //new values to be used
	}
      //using the "value" variable to do some maths down the line
}

If you carefully read through your calculations function, what does it do?

• it sets the input value to 4
• then it looks if the input value is !== 4 (how can that ever be true, you’ve just set it to 4)

[Plebian]

Yes, the initial value is set to 4.
I guess my logic is trying to be, if my value I type in the inputtextbox is not 4, it will then use this newly typed value in our variable named value

[jsdisco]

That’s not how it works, it’s not just the initial value. You always set it back to 4 whenever someone clicks the button.

You can set an initial value in your HTML:

<input id="inputtextbox" value="4">

Then in your code, read the new value from the input if someone clicks the button:

var value = Number(document.getElementById("inputtextbox").value);

This by the way doesn’t work:

if (inputtextbox !== 4)

inputtextbox is the HTML element, not the value.