Develop Reference

Copying TD value to dynamically created input inside a TD

I have a table with dynamically generated td's that contain text inputs and I need to get the value from the first td in the row and insert into one of the inputs depending on what I select in a <select>. This is trigger by a button.
So far I'm able to get the the value I need with first-child and from my select I have the value of the option same as the class of the inputs.
$("#t_a").click(function() {
var selected = $('select[name=t_r]').val();
$("table tr").each(function() {
var s = $(this).find('td:first-child').html();
$(this).find('.' + selected).attr("value", s);
});
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<select id="t_r" name="t_r" style="width:200px;">
<option value="1234">Option 1234</option>
<option value="1235">Option 1235</option>
<option value="1236">Option 1236</option>
</select>
<input type="button" name="t_a" id="t_a" value="Apply" />
<table>
<tr>
<td>123</td>
<td><input type="text" id="a_1234" class="1234" value=""></td>
<td><input type="text" id="a_1235" class="1235" value=""></td>
<td><input type="text" id="a_1236" class="1236" value=""></td>
</tr>
<tr>
<td>321</td>
<td><input type="text" id="b_1234" class="1234" value=""></td>
<td><input type="text" id="b_1235" class="1235" value=""></td>
<td><input type="text" id="b_1236" class="1236" value=""></td>
</tr>
<tr>
<td>456</td>
<td><input type="text" id="c_1234" class="1234" value=""></td>
<td><input type="text" id="c_1235" class="1235" value=""></td>
<td><input type="text" id="c_1236" class="1236" value=""></td>
</tr>
</table>

With the help of monkawitz and user7290573 I was able to solve my problem by using val() instead of attr().
Thank you Tim Lewis for the guidance.

How To get Multidimensional Input Fields Array Index with JavaScript?

This my sample HTML form with multidimensional input fields
<tr>
<td><input name="diameter[0][top]" type="text" id="diameter_top0" size="5" class="diameter" /></td>
<td><input name="diameter[0][bottom]" type="text" id="diameter_bottom0" size="5" class="diameter" /></td>
</tr>
<tr>
<td><input name="diameter[1][top]" type="text" id="diameter_top1" size="5" class="diameter" /></td>
<td><input name="diameter[1][bottom]" type="text" id="diameter_bottom1" size="5" class="diameter" /></td>
</tr>
<tr>
<td><input name="diameter[5][top]" type="text" id="diameter_top5" size="5" class="diameter" /></td>
<td><input name="diameter[5][bottom]" type="text" id="diameter_bottom5" size="5" class="diameter" /></td>
</tr>
Lets say I'm writing on ID diameter_bottom5 input. And onkeyup I need index of diameter of input field. In this example it would be 5.
I don't want to use regex or slice in name or id attribute.
I don't want to create custom attribute to store index.
How can get multidimensional input fields array index in which I'm currently typing using JavaScript?

If you are O.K. with the 'order index' of your table data, you can do it like that (obviously, this wouldn't work if your 'numbering' won't match given order and/or amount of inputs):
const tableData = [...document.getElementById('myTable').getElementsByTagName('td')]
tableData.forEach((item, i) => item.addEventListener('keyup', () => {
console.log(i)
}), false);
<table id='myTable'>
<tr>
<td><input name="diameter[0][top]" type="text" id="diameter_top0" size="5" class="diameter" /></td>
<td><input name="diameter[0][bottom]" type="text" id="diameter_bottom0" size="5" class="diameter" /></td>
</tr>
<tr>
<td><input name="diameter[1][top]" type="text" id="diameter_top1" size="5" class="diameter" /></td>
<td><input name="diameter[1][bottom]" type="text" id="diameter_bottom1" size="5" class="diameter" /></td>
</tr>
<tr>
<td><input name="diameter[5][top]" type="text" id="diameter_top5" size="5" class="diameter" /></td>
<td><input name="diameter[5][bottom]" type="text" id="diameter_bottom5" size="5" class="diameter" /></td>
</tr>
</table>

Re-Using JavaScript Function

Creating a cake ordering form, and the # of cakes available can vary from month to month. I am attempting to tweak a JS function created from #Anderson Contreira but in my fiddle it does not work. Here is what I have thus far - Why does nothing change when I enter a quantity?
https://jsfiddle.net/2uack1w6/
Syntax
JS
function calculate(el){
var quantity = el.val();
var id = el.attr("id").replace("item_","").replace("_qty","");
var data = {quantity: quantity,id:id};
var targetTax = $("#item_"+id+"_tax");
var targetTotalPrice = $("#item_"+id+"_totalprice");
$.post($.post(window.alert("It's been one or two or three entered");
});
}
var qty = $("#item_1_qty");
var qty1 = $("#item_2_qty");
var qty2 = $("#item_3_qty");
qty.on("keyup",function(){
window.alert("It's been one or two or three entered");
});
HTML/PHP
<body>
<form id="Form1" runat="server">
<div id="Form1" runat="server">
<table id="table1" border="1">
<tr>
<th>Item</th>
<th>Price</th>
<th>Quantity</th>
<th>Tax</th>
<th>Total</th>
</tr>
<tr>
<td><label for="lblChoccake">Choc Cake</label></td>
<td><label for="lblitem1price">$25.00</label></td>
<td><input type="text" id="item_1_qty" name="txtitem1qty" value="0" maxlength="10" size="3"></td>
<td><input type ="text" id="item_1_tax" name="txtitem1tax" maxlength="10" size="3" readonly></td>
<td><input type="text" id="item_1_totalprice" name="txtitem1totalprice" maxlength="10" size="3" readonly></td>
</tr>
<tr>
<td><label for="lblLemonFudgecake">Lemon Fudge Cake</label></td>
<td><label for="lblitem2price">$15.00</label></td>
<td><input type="text" id="item_2_qty" name="txtitem1qty" value="0" maxlength="10" size="3"></td>
<td><input type ="text" id="item_2_tax" name="txtitem1tax" maxlength="10" size="3" readonly></td>
<td><input type="text" id="item_2_totalprice" name="txtitem1totalprice" maxlength="10" size="3" readonly></td>
</tr>
<tr>
<td><label for="lblCoconut">Coconut Cake</label></td>
<td><label for="lblitem3price">$35.00</label></td>
<td><input type="text" id="item_3_qty" name="txtitem1qty" value="0" maxlength="10" size="3"></td>
<td><input type ="text" id="item_3_tax" name="txtitem1tax" maxlength="10" size="3" readonly></td>
<td><input type="text" id="item_3_totalprice" name="txtitem1totalprice" maxlength="10" size="3" readonly></td>
</tr>
</table>
</div>
</form>
</body>

jQuery(function($) {
var qty = $("#item_1_qty");
var qty1 = $("#item_2_qty");
var qty2 = $("#item_3_qty");
qty.on("keyup",function(){
alert("It's been one or two or three entered");
});
});
Try this, you are assigning variables before the document has actually loaded.

Take a look here: https://jsfiddle.net/andersoncontreira/mtu6syby/1/
You can make some changes and will work well:
Add a class in each input of item_?_qty e.g.: <input type="text" id="item_1_qty" class="item_qty" />
In your javascript, you can leave the call generic:
jQuery(document).ready(function(){
//you can use a class for help you
$(".item_qty").on("keyup",function(){
//window.alert("It's been one or two or three entered");
calculate($(this));
});
});

Update total in table row with jquery

I have a table
<table>
<tbody>
<tr>
<td><input type="text" name="quantity" /></td>
<td><input type="text" name="price" /></td>
<td><input type="text" name="total" disabled />
</tr>
<tr>
<td><input type="text" name="quantity" /></td>
<td><input type="text" name="price" /></td>
<td><input type="text" name="total" disabled />
</tr>
<tr>
<td><input type="text" name="quantity" /></td>
<td><input type="text" name="price" /></td>
<td><input type="text" name="total" disabled />
</tr>
<tr>
<td><input type="text" name="quantity" /></td>
<td><input type="text" name="price" /></td>
<td><input type="text" name="total" disabled />
</tr>
</tbody>
</table>
How can I update the total input field when a change in quantity or price happens?
I have thought of something like
$('table tbody tr td').filter(':nth-child(1), :nth-child(2)').children('input').change(function() {
$(this).parent('td').siblings('td').filter(':nth-child(3)').val(?);
});
but it seems a bit unhandy.

You can use:
$('table tbody tr td').find('input').keyup(function() {
var total=0;
total=(parseInt($(this).parent('td').siblings('td').not(':nth-child(3)').find('input').val())||0)+(parseInt($(this).val())||0);
$(this).closest('tr').find('input:last').val(total)
});
Working Demo

Much easy to read and control if you can assign some dummy class to quantity, price and total input.
Something like this:
HTML
<table>
<tbody>
<tr>
<td><input type="text" class="qty" name="quantity" /></td>
<td><input type="text" class="prc" name="price" /></td>
<td><input type="text" class="total" name="total" disabled />
</tr>
<tr>
<td><input type="text" class="qty" name="quantity" /></td>
<td><input type="text" class="prc" name="price" /></td>
<td><input type="text" class="total" name="total" disabled />
</tr>
<tr>
<td><input type="text" class="qty" name="quantity" /></td>
<td><input type="text" class="prc" name="price" /></td>
<td><input type="text" class="total" name="total" disabled />
</tr>
<tr>
<td><input type="text" class="qty" name="quantity" /></td>
<td><input type="text" class="prc" name="price" /></td>
<td><input type="text" class="total" name="total" disabled />
</tr>
</tbody>
</table>
Script
$('table tbody tr').find('.qty, .prc').on('keyup',function() {
var parent = $(this).parents('tr');
var quantity = parseInt(parent.find('.qty').val())||0;
var price = parseInt(parent.find('.prc').val())||0;
parent.find('.total').val(quantity*price);
});
Check working example here

Personally, i prefer not to select elements by their position. If you wind up changing them later, or adding another your code is broken.
I would do something like:
$(this).closest('tr').find('input[name=total]').val(?);

Get values from table of text fields javascript

I have a form which actually is a table of text fields. The html looks like this:
<form>
<table id="table">
<tr>
<th>Player</th>
<th>Number</th>
<th>Con.per.day</th>
<th>P.100.kg</th>
<th>P.day</th>
<th>I.month</th>
</tr>
<tr>
<td><input type="text" /></td>
<td><input type="text" /></td>
<td><input type="text" /></td>
<td><input type="text" /></td>
<td><input type="text" /></td>
<td>Result</td>
</tr>
<tr>
<td><input type="text" /></td>
<td><input type="text" /></td>
<td><input type="text" /></td>
<td><input type="text" /></td>
<td><input type="text" /></td>
<td>Result</td>
</tr>
<tr>
<td><input type="text" /></td>
<td><input type="text" /></td>
<td><input type="text" /></td>
<td><input type="text" /></td>
<td><input type="text" /></td>
<td>Result</td>
</tr>
</table>
<input type="button" name="rank" value="Rank" onClick="rankPlayers(this.form)"/>
</form>
I would like to iterate all fields and get the values at the press of the button, but I get undefined returned in the console log. I don't want to use IDs for each field as I want to do some column operations (add, multiply). My script for the first column looks like this:
function rankPlayers(){
var table=document.getElementById("table");
for(var i=1; i<table.rows.length;i++){
console.log(table.rows[i].cells[0].value);
}
}
Any tips? Thanks

You need to select the input from the cell:
// ------------------------------------v
console.log(table.rows[i].cells[0].firstChild.value);
If you could have siblings (even whitespace) around the inputs, then you can use the .children collection to target the correct element.
// ------------------------------------v
console.log(table.rows[i].cells[0].children[0].value);

You can change your loop to:
var table=document.getElementsByTagName("td");
for(var i=1; i<table.length;i++){
console.log(table[i].firstChild.value);
}
This gets all td elements, loops them, and checks the firstChild value