How calculate a total sales in an HTML table?

Don
July 7, 2023
148 views
2 votes
3 Answers

I am unable to find a way to total sales.

//Quarts 1
function updateOrder1() {
  const X = 13;
  var Y = document.getElementById("Quarts");
  var value = Y[Y.selectedIndex].text;
  var Z = value * X;
  document.getElementById("total1").value = "$" + Z.toFixed(2)
}
//Pints 2  
function updateOrder2() {
  const X = 8;
  var Y = document.getElementById("Pints");
  var value = Y[Y.selectedIndex].text;
  var Z = value * X;
  document.getElementById("total2").value = "$" + Z.toFixed(2)
}

<table border=1 px>
  <tr>
    <td><b>Quarts</b></td>
    <td>
      <form>
        <select id="Quarts" onchange="updateOrder1();">
          <option>Select</option>
          <option>1</option>
          <option>2</option>
          <option>3</option>
          <option>4</option>
          <option>5</option>
        </select>
    </td>
    
    <td width="3%">
      <input type="text" id="total1" name="total1" value="0" readonly="readonly" />
    </td>
  </tr>

  <tr>
    <td><b>Pints</b></td>
    <td>
      <form>
        <select id="Pints" onchange="updateOrder2();">
          <option>Select</option>
          <option>1</option>
          <option>2</option>
          <option>3</option>
          <option>4</option>
          <option>5</option>
        </select>
    </td>
    <td>
      <input type="text" id="total2" name="total2" value="0" readonly="readonly" />
    </td>
  </tr>

  <tr>
    <td></td>
    <td>
      Total
      </div>
    </td>
    <td></td>
  </tr>
</table>

Tags: html javascript

Answers

React to change events of your select boxes inside the table and use Array::reduce to calculate the total, then insert it into the total cell:

//Quarts 1

document.querySelector('table').addEventListener('change', e => {

   // find all cells with totals in the table
   const totalCells = e.target.closest('table').querySelectorAll('[name^=total]');

   // calc sum of the totals with parsing a currencty into a float number
   const total = [...totalCells].reduce((sum, elem) => sum + parseFloat(elem.value.match(/[d.]+/)?.[0] || 0), 0);
   
   orderTotal.textContent = '$' + total.toFixed(2);
   

});

function updateOrder1() {
  const X = 13;
  var Y = document.getElementById("Quarts");
  var value = Y[Y.selectedIndex].text;
  var Z = value * X;
  document.getElementById("total1").value = "$" + (Z||0).toFixed(2)
}
//Pints 2  
function updateOrder2() {
  const X = 8;
  var Y = document.getElementById("Pints");
  var value = Y[Y.selectedIndex].text;
  var Z = value * X;
  document.getElementById("total2").value = "$" + (Z||0).toFixed(2)
}

<table border=1 px>
  <tr>
    <td><b>Quarts</b></td>
    <td>
      <form>
        <select id="Quarts" onchange="updateOrder1();">
          <option>Select</option>
          <option>1</option>
          <option>2</option>
          <option>3</option>
          <option>4</option>
          <option>5</option>
        </select>
    </td>
    
    <td width="3%">
      <input type="text" id="total1" name="total1" value="0" readonly="readonly" />
    </td>
  </tr>

  <tr>
    <td><b>Pints</b></td>
    <td>
      <form>
        <select id="Pints" onchange="updateOrder2();">
          <option>Select</option>
          <option>1</option>
          <option>2</option>
          <option>3</option>
          <option>4</option>
          <option>5</option>
        </select>
    </td>
    <td>
      <input type="text" id="total2" name="total2" value="0" readonly="readonly" />
    </td>
  </tr>

  <tr>
    <td></td>
    <td>
      Total
      </div>
    </td>
    <td id="orderTotal"></td>
  </tr>
</table>

Here’s one approach. It’s best to reuse functions and pass in the value that changes rather than having separate functions for each case. You can update adjacent elements based on the event target’s position in the document rather than by ID.

Note that I’ve wrapped a single form around the entire table instead of having separate forms. Technically you don’t even need a form since you’re not submitting it anywhere.

function updateOrder(event, price) {
  const selectedVal = event.currentTarget.value;
  let rowCost = (selectedVal * price).toFixed(2);
  const row = event.target.closest('tr');
  const input = row.querySelector('td:last-child input');
  
  // deal with deselection
  if (rowCost === 'NaN') rowCost = 0;

  // use a data attribute to store the numeric row total for later use
  input.setAttribute('data-val', rowCost);
  input.value = "$" + rowCost;

  updateTotal();
}

function updateTotal() {
  const rowTotalEls = document.querySelectorAll('#priceTable td:last-child input');
  let grandTotal = 0;

  rowTotalEls.forEach(function(el) {
    const rowCost = el.getAttribute('data-val');

    if (rowCost) {
      grandTotal += parseFloat(rowCost);
    }
  });

  if (grandTotal > 0) {
    document.querySelector('#total').textContent = '$' + grandTotal.toFixed(2);
  }
}

<form>
  <table id="priceTable" style="border: 1px solid;">
    <tr>
      <td><b>Quarts</b></td>
      <td>
        <select id="Quarts" onchange="updateOrder(event, 13);">
          <option>Select</option>
          <option>1</option>
          <option>2</option>
          <option>3</option>
          <option>4</option>
          <option>5</option>
        </select>
      </td>

      <td width="3%">
        <input type="text" id="total1" name="total1" value="0" readonly="readonly" />
      </td>
    </tr>

    <tr>
      <td><b>Pints</b></td>
      <td>
        <select id="Pints" onchange="updateOrder(event, 8);">
          <option>Select</option>
          <option>1</option>
          <option>2</option>
          <option>3</option>
          <option>4</option>
          <option>5</option>
        </select>
      </td>
      <td>
        <input type="text" id="total2" name="total2" value="0" readonly="readonly" />
      </td>
    </tr>

    <tr>
      <td></td>
      <td>
        Total
      </td>
      <td id="total"></td>
    </tr>
  </table>
</form>

Your HTML is malformed on <form> the bees died
Use events in the code not in the HTML
Using tables for layout just makes things ‘harder’ to style so I used a set of grids in grids
Added the grand total update as a function
Put the amounts for each in a data attribute so we don’t need global variables and can still update
Put some ugly borders around stuff just to show what is where
Used * 1 various places to avoid parsing numbers
Moved all the style to CSS where it is easier to maintain
Changed names to better reflect use etc.

function updateGrandTotal() {
  const ptotal = document.getElementById("pint-total");
  const pAmount = ptotal.dataset.currentamount * 1;
  const qtotal = document.getElementById("quart-total");
  const qAmount = qtotal.dataset.currentamount * 1;

  const formattedTotal = '$' + ((pAmount + qAmount).toFixed(2));
  console.log(pAmount, qAmount, formattedTotal);
  document.querySelector('.grand-total-container').textContent = formattedTotal;
}

function handleQuartsChange(event) {
  const unitPerQuart = 13;
  const quartCount = event.currentTarget.value * 1;
  const amount = quartCount * unitPerQuart;
  const total = document.getElementById("quart-total");
  total.dataset.currentamount = amount;
  total.textContent = "$" + amount.toFixed(2);
  updateGrandTotal();
}

function handlePintsChange(event) {
  const unitPerPint = 8;
  const pintCount = event.currentTarget.value * 1;
  const amount = pintCount * unitPerPint;
  const total = document.getElementById("pint-total");
  total.dataset.currentamount = amount;
  total.textContent = "$" + amount.toFixed(2);
  updateGrandTotal()
}

let quarts = document.querySelector('#quarts');
quarts.addEventListener('change', handleQuartsChange);
let pints = document.querySelector('#pints');
pints.addEventListener('change', handlePintsChange);

body,
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-size: 16px;
}

body {
  // super center on the page body
  display: grid;
  place-items: center;
  grid-gap: 1em;
}

.form-container {
  border: 1px solid black;
  // super center on the container
  display: grid;
  place-items: center;
  grid-gap: 1em;
}

.block-container {
  display: grid;
  grid-template-rows: auto 1fr;
  grid-gap: 1em;
  border: solid 1px blue;
  place-items: center;
}

.header-item {
  font-weight: bold;
}

.total-container {
  padding: 0.5em;
  border: solid yellow 2px;
}

<div class="form-container">
  <div class="block-container">
    <label class="header-item">Quarts</label>
    <select id="quarts">
      <option>Select Quarts</option>
      <option>1</option>
      <option>2</option>
      <option>3</option>
      <option>4</option>
      <option>5</option>
    </select>
    <div class="total-container">
      <div id="quart-total" data-currentamount="0">0</div>
    </div>
  </div>
  <div class="block-container">
    <label class="header-item">Pints</label>
    <select id="pints">
      <option>Select Pints</option>
      <option>1</option>
      <option>2</option>
      <option>3</option>
      <option>4</option>
      <option>5</option>
    </select>
    <div class="total-container">
      <div id="pint-total" data-currentamount="0">0</div>
    </div>
  </div>
  <div class="block-container total-container">
    <div>Grand Total</div>
    <div class="grand-total-container">$0</div>
  </div>
</div>

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