Void function return value is used JavaScript [duplicate]

Question

let btn = document.createElement("button");
btn.id = "submitBV"
let firstRow = 12
let lastRow = 59
btn.addEventListener("click", autoInput(firstRow, lastRow))

function autoInput(firstRow, lastRow){
    print()
}

It tells me Void function return value is used (screenshot).

After I add a return 1, it doesn't solve as well (screenshot2).

Answer 1

Yes, because you are invoking the autoInput function which does not return something (void) valid. To handle this, to need to pass a function in order to be called when the click event is triggered by the button. In this case, you can add a simple function to do this.

btn.addEventListener("click", function() { autoInput(firstRow, lastRow); })

If you have a function which returns another function (if you are new to javascript, yes, it is possible) it may work fine, which is not your case on the autoInput function.