Make Default Checked Radio Button Value Display on HTML?

Question

So I have my JS Function that checks if a radio button is selected, then displays the value on my HTML like normal.

My problem is it only works if the default value is set to 0. How would I change this so that if I use the checked option on $5 in my HTML radio input, that it will also display that value in my browser?

If I change my checked option to a different tip value, it still shows 0 as the starting value since I didn't click anything.

Here is my JS Code

window.tip = 0;

const tipTotal = document.getElementById("tip");
const orderTotal = document.getElementById("total");

document.addEventListener("click", ({
      target
    }) => {
      if (target.className === "tips" && target.checked) {
        window.tip = parseInt(target.value);
      } else {
        return;

        tipTotal.textContent = `$${window.tip}`;
      }

I display the selected radio button here

<td id="tip">$0.00</td>

Here is my HTML Radio Buttons

<input type="radio" value="0" id="tip0" name="tip" class="tips" />
<label for="tip0">$0</label>
</div>
<div>
  <input type="radio" value="300" id="tip1" name="tip" class="tips" />
  <label for="tip1">$3</label>
</div>
<div>
  <input type="radio" value="500" id="tip2" name="tip" class="tips" checked //here is the default checked option for $5 />
  <label for="tip2">$5</label>
</div>  

So by default, my app will show the tip: $5 option checked, however, the HTML on the browser for Tips will says Tip: $0.00 instead of Tip: $5.00 unless I click it

Answer 1

It sets window.tip only when a radio button is clicked because you added an event listener that fires only on click. You can add an on load event listener.

window.tip = 0;

const tipTotal = document.getElementById("tip");
const orderTotal = document.getElementById("total");

document.addEventListener("click", ({ target }) => {
    if (target.className === "tips" && target.checked) {
      window.tip = parseInt(target.value);
    }
});

document.addEventListener("load", () => {
    const selectedOption = document.querySelector(".tips:checked");
    window.tip = parseInt(selectedOption.value);
});

I also removed an unnecessary else statement in the first event listener.

EDIT

Automatically update tipTotal text:

window.tip = 0;

const tipTotal = document.getElementById("tip");
const orderTotal = document.getElementById("total");

function updateTip(value) {
    window.tip = parseInt(value);
    tipTotal.textContent = window.tip;
}

document.addEventListener("click", ({ target }) => {
    if (target.className === "tips" && target.checked) {
      updateTip(target.value);
    }
});

document.addEventListener("load", () => {
    const selectedOption = document.querySelector(".tips:checked");
    updateTip(selectedOption.value);
});

Answer 2

First, you've got a Global variable called "tip" and an element with an id of "tip" as well. Elements with id s also become Global and so you've got a conflict in naming.

Next, you need to initially update that td in your JS and also when the tip amount changes.

 let tip = 0; const tipTotal = document.getElementById("tipAmount"); const orderTotal = document.getElementById("total"); // Initialize the table data tipTotal.textContent = document.querySelector(".tips:checked").value; document.addEventListener("click", function(event) { // No need to see if it's checked because clicking // on a radio button makes it checked and this code // wouldn't be called if you didn't click it. if (event.target.className === "tips") { tipTotal.textContent = event.target.value // Update the table } });

 <div> <input type="radio" value="0" id="tip0" name="tip" class="tips"> <label for="tip0">$0</label> </div> <div> <input type="radio" value="300" id="tip1" name="tip" class="tips"> <label for="tip1">$3</label> </div> <div> <input type="radio" value="500" id="tip2" name="tip" class="tips" checked> <label for="tip2">$5</label> </div> <table> <tr><td id="tipAmount"></td></tr> </table>

Answer 3

Simply trigger a tip2 radio button click event:

document.getElementById("tip2").click();

For example:

 const tipTotal = document.getElementById("tip"); const tipButton = document.getElementById("tip2"); tipButton.addEventListener("click", ({ target }) => { if (target.className === "tips" && target.checked) { window.tip.innerText = "$" + target.value; } else { return; } }); // activate click event on tip2 radio button tipButton.click();

 <div id="tip">$0.00</div> <div> <input type="radio" value="5.00" id="tip2" name="tip" class="tips" /> <label for="tip2">$5</label> </div>