为什么我的 IF 语句在 JavaScript 中不起作用？

Question

Can someone explain why my if statement doesn't work in the displayStorageSizeToConvert() function? Please and thank you!

var userInput = document.getElementById("userInput");
var kbButton = document.getElementById("k");
var mbButton = document.getElementById("mbButton");
var KilobyteDisplay = document.getElementById('KilobyteDisplay');
var megabyteDisplay = document.getElementById('megabyteDisplay');
var submitButton = document.getElementById('submit');

function displayStorageSizeToConvert() {
    if (kbButton.clicked === true) {    
        return convertFrom.innerHTML = "KB";    
    }
    else {
        return convertFrom.innerHTML = "MB";
    }
}


    function convertStorageSizeFrom() {
    if(convertFrom.value === "KB") {
        KilobyteDisplay.innerHTML = userInput.value + " KB";
        megabyteDisplay.innerHTML = userInput.value / 1000 + " MB";
    }
}

Answer 1

It doesn't look like you're invoking your function anywhere.

Also, you should attach this function to a click handler:

function displayInKB() {
    convertFrom.innerHTML = "KB";    
}

function displayInMb() {
    convertFrom.innerHTML = "MB";    
}

kbButton.addEventListener('click', displayInKb);
mbButton.addEventListener('click', displayInMb)

Answer 2

You are not currently ever calling/triggering displayStorageSizeToConvert().

I think you are wanting to create a listener. You can add it like this:

kbButton.addEventListener('click', () => convertForm.innerHTML = "KB")