Develop Reference

Add row and td element and a checkbox in the table

I have the following table structure
<form method=POST class='form leftLabels'>
<table >
<tr >
<th >Code:</th>
<td ><input type='text' name='f[id]' size='60' value='10' /></td>
</tr>
<tr ><th >Name:</th>
<td ><input type='text' name='f[name]' size='60' value='Aa' /></td>
</tr>
// <<<< Here I would like to add a row
<tr >
<td class=' nogrid buttonsClass'><button type=submit>Save</button>
</td>
</tr>
</table>
</form>
The row that I am trying to add should have the following html:
<tr>
<th> Delete the record?</th>
<td><input type='checbox' name='delete' value=1></td>
</tr>
I have the following Javascript / jQuery code:
var trCnt=0;
$('table tr').each(function(){
trCnt++;
});
rowToInsertCheckbox = trCnt - 1;
$('table').after(rowToInsertCheckbox).append(
$(document.createElement('tr')),
$(document.createElement('td').html('Delete the record'),
$(document.createElement('td').html('Checkbox here?')),
);
which does find the right row after which the insert should be done, but the code does not work.

after() adds the new content after the target element, but outside it. tr need to be inside the table. In addition you need to append the td to the tr, not the table.
To place the new tr in your target position you can select the last tr in the table and use insertBefore(), like this:
let $newRow = $('<tr />').insertBefore('table tr:last');
$('<td>Delete the record?</td>').appendTo($newRow);
$('<td><input type="checkbox" name="delete" value="1"></td>').appendTo($newRow);
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<form method="POST" class="form leftLabels">
<table>
<tr>
<th>Code:</th>
<td><input type="text" name="f[id]" size="60" value="10" /></td>
</tr>
<tr>
<th>Name:</th>
<td><input type="text" name="f[name]" size="60" value="Aa" /></td>
</tr>
<tr>
<td class="nogrid buttonsClass"><button type="submit">Save</button></td>
</tr>
</table>
</form>

One way to locate the row after which the content should be added is:
var tr = $("th").filter(function () {
return $(this).text() == "Name:";
}).closest("tr");
Then add the row:
$(tr).after("<tr><th> Delete the record?</th><td><input type='checkbox' name='delete' value=1></td></tr>");
$(document).ready(function() {
var tr = $("th").filter(function() {
return $(this).text() == "Name:";
}).closest("tr");
$(tr).after("<tr><th>Delete the record?</th>" +
"<td><input type='checkbox' name='delete' value=1></td>" +
"</tr>");
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<form method=POST class='form leftLabels'>
<table>
<tr>
<th>Code:</th>
<td><input type='text' name='f[id]' size='60' value='10' /></td>
</tr>
<tr>
<th>Name:</th>
<td><input type='text' name='f[name]' size='60' value='Aa' /></td>
</tr>
<tr>
<td class=' nogrid buttonsClass'><button type=submit>Save</button>
</td>
</tr>
</table>
</form>

Get the value of a column entered by the user

<form id="form1" runat="server">
<table border="1" id="ResultSheet">
<tr id ="Name">
<td> Student Name</td>
<td><input type="text" /></td>
</tr>
<tr>
<td>Subject Name</td>
</tr>
<tr>
<td>Maths</td>
<td><input type="text" /></td>
</tr>
<tr>
<td>Science</td>
<td><input type ="text" /></td>
</tr>
<tr>
<td>English</td>
<td><input type ="text" /></td>
</tr>
</table>
</form>
I have this table and now I want to get the value of each of input type. how do I get it.
I've tried:
document.getElementById("ResultSheet").rows[2].cells.item(0).innerHTML);
But it did not return anything.

You could use querySelectorAll() like :
document.querySelectorAll('#ResultSheet input');
The loop through the result like the snippet below shown.
Hope this helps.
var inputs = document.querySelectorAll('#ResultSheet input');
for(var i=0;i<inputs.length;i++){
console.log(inputs[i].value);
}
<form id="form1" runat="server">
<table border="1" id="ResultSheet">
<tr id ="Name">
<td> Student Name</td>
<td><input type="text" value="1"/></td>
</tr>
<tr>
<td>Subject Name</td>
</tr>
<tr>
<td>Maths</td>
<td><input type="text" value="2"/></td>
</tr>
<tr>
<td>Science</td>
<td><input type ="text" value="3"/></td>
</tr>
<tr>
<td>English</td>
<td><input type ="text" value="4"/></td>
</tr>
</table>
</form>

Use <form> property elements: https://developer.mozilla.org/en-US/docs/Web/API/HTMLFormElement/elements
Example: https://jsfiddle.net/8co9v0ye/

Passing the value of a td cell thru onclick Javascript function

I have a single column html table with 20 rows, containing strings (used as tags):
<table id="table_of_tags">
<tr>
<td id="c_01" onclick="Pass_Content_Of_Cell(_param)">Tree</td>
</tr>
<tr>
<td id="c_02" onclick="Pass_Content_Of_Cell(_param)">Flower</td>
</tr>
....
</table>
The function Pass_Content_of_Cell() must pass the contents of the cells clicked and concatenate the tags in a single string of tags: "Flower;Tree;" (WHAT it does is not relevant).
The user can click randomly on any tag and in any order he likes.
Question: What exactly should I use for _param ? I tried this.value and this.text and didn't get anything useful.

Try this
onclick="Pass_Content_Of_Cell(this.innerText)"
or if you want the markup,
onclick="Pass_Content_Of_Cell(this.innerHTML)"

Try this.innerText
<table id="table_of_tags">
<tr><td id="c_01" onclick="Pass_Content_Of_Cell(this.innerText)">Tree</td><tr>
<tr><td id="c_02" onclick="Pass_Content_Of_Cell(this.innerText)">Flower</td><tr>
</table>

If your are using a loop to generate the markup, why you simply didn't do something like:
<tr><td onClick="doSomething('$param')">$param</td></tr>
I cannot imagine the list is hardcoded...

<script type="text/javascript">
function save(val1)
{
alert("you have saved Employee "+document.getElementById(val1).innerText);
}
function del(val1)
{
alert("you have deleted Employee "+document.getElementById(val1).innerText);
}
</script>
<table border="1">
<tr>
<th>EmployeeID</th>
<th>Name</th>
<th>Email</th>
<th>Phone</th>
<th>Option</th>
</tr>
<tr>
<td>1590</td>
<td id="c1">Venkatesh</td>
<td>venki#w3s.com</td>
<td>9943243433</td>
<td><input type="checkbox" name="chk" id="chk"></td>
<td><input type="button" value="Delete" id="dlt1" name="dlt1" onclick="del('c1');"><input type="button" value="Save" id="sv1" name="sv1" onclick="save('c1');"></td>
</tr>
<tr>
<td>1591</td>
<td id="c2">amarnath</td>
<td>amar#w3s.com</td>
<td>9943113433</td>
<td><input type="checkbox" name="chk" id="chk"></td>
<td><input type="button" value="Delete" id="dlt1" name="dlt1" onclick="del('c2');"><input type="button" value="Save" id="sv1" name="sv1" onclick="save('c2');"></td>
</tr>
<tr>
<td>1601</td>
<td id="c3">naveen</td>
<td>navs#w3s.com</td>
<td>9943113433</td>
<td><input type="checkbox" name="chk" id="chk"></td>
<td><input type="button" value="Delete" id="dlt1" name="dlt1" onclick="del('c3');"><input type="button" value="Save" id="sv1" name="sv1" onclick="save('c3');"></td>
</tr>
</table>

How to get all values in <tr> of html <table>

I want to get all values of td when I click the checkbox which is fourth coloumn.
Also I want to get the smallest among ID and Optional ID
<table><form method='GET'>
<tr>
<th>Name</th>
<th>ID</th>
<th>Optional ID</th>
<th>Approved</th>
</tr>
<tr>
<td>Sumit</td>
<td>4</td>
<td><input type='text' name='txt`[]' /></td>
<td><input type='checkbox' name='chk[]' /></td>
</tr>`
<tr>
<td>Harsh</td>
<td>3</td>
<td><input type='text' name='txt`[]' /></td>
<td><input type='checkbox' name='chk[]' /></td>
</tr>`
<tr><td colspan=4><input type='submit' name='sub1' /></td></tr>
</form>

I think this is what you're looking for:
function Start() {
$('#SubmitBtn').click(function () {
$('#TheTable').find('tr').each(function () {
if ($(this).find('input').eq(1).is(':checked') === true) {
alert($(this).find('input').val());
}
});
});
}
$(Start);
There's a jsFiddle here

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