I have searched for a solution to this issue everywhere but nothing has worked. I have successfully pulled the first column but I am unable to pull the 2nd column. The following code pulls the entire 1st column successfully.
I changed .cells
to [1]
and it pulls nothing. I have tried :nth-child(1)
but that doesn't work either. I feel I am missing something very trivial. Any help is very much appreciated.
function F0416()
{
var tab = document.getElementById('partTable');
var l = tab.rows.length;
var s = '';
for ( var i = 0; i < l; i++ )
{
var tr = tab.rows[i];
var cll = tr.cells[0];
s += ' ' + cll.innerText;
}
document.write(s);
}
I have searched for a solution to this issue everywhere but nothing has worked. I have successfully pulled the first column but I am unable to pull the 2nd column. The following code pulls the entire 1st column successfully.
I changed .cells
to [1]
and it pulls nothing. I have tried :nth-child(1)
but that doesn't work either. I feel I am missing something very trivial. Any help is very much appreciated.
function F0416()
{
var tab = document.getElementById('partTable');
var l = tab.rows.length;
var s = '';
for ( var i = 0; i < l; i++ )
{
var tr = tab.rows[i];
var cll = tr.cells[0];
s += ' ' + cll.innerText;
}
document.write(s);
}
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edited Jul 27, 2017 at 13:47
Brian Tompsett - 汤莱恩
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asked Feb 28, 2014 at 13:57
JohnBJohnB
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3 Answers
Reset to default 10First and foremost. Never ever use l
(lower case el) as a variable. It is far to similar to 1
(one). Also be careful with upper case "o", and upper-case "i". Lowercase "o" is also often disliked.
It might look OK now, but when you review it in 6 months or a year, perhaps not so much. Also consider others might have to both read and modify your code.
Enough about that.
Your code, as it is, should work. If you do not get the desired result then the problem is elsewhere.
Make it reusable
However, to simplify the code and make it easier to re-use, you can add a parameter for id of the table as well as desired column. Resulting function could be something like this, with some extra checks:
function getColumn(table_id, col) {
var tab = document.getElementById(table_id);
var n = tab.rows.length;
var i, s = null, tr, td;
// First check that col is not less then 0
if (col < 0) {
return null;
}
for (i = 0; i < n; i++) {
tr = tab.rows[i];
if (tr.cells.length > col) { // Check that cell exists before you try
td = tr.cells[col]; // to access it.
s += ' ' + td.innerText;
} // Here you could say else { return null; } if you want it to fail
// when requested column is out of bounds. It depends.
}
return s;
}
var txt = getColumn('partTable', 2);
Check for failure
By using null
as initial value for s
, we can compare returned result with null
to see if it was successful.
if (txt === null) {
// Report error, or at least not work on "txt".
}
Simplify
Once you really understand it you can, if you want, simplify the loop to something like this:
for (i = 0; i < n; i++) {
if (tab.rows[i].cells.length > col) {
s += ' ' + tab.rows[i].cells[col].innerText;
}
}
Use Array:
If you are going to use the cells one by one the best approach would be to return an Array instead of a string. Then you can loop the array, or if you want it as a string simply join it with desired delimiter. This would most likely be the most useful and reusable function.
// In function:
arr = [];
// In loop:
arr.push(tab.rows[i].cells[col].innerText);
var cells = getColumn("the_id", 2);
var text = cells.join(' ');
Demo:
Fiddle demo with array
Speed.
If your table cells does not contain any <script>
or <style>
, which they should not, you can also consider using textContent
over innerText
. Especially if table is large. It is a much faster. Here is a short article on the subject from Kelly Norton:
- INNERTEXT VS. TEXTCONTENT
// This pulls all columns
function getAllCells(table) {
var result = [];
for(var i = 0, j = 0, l = table.rows.length, l2 = 0; i < l; i++) {
for(j = 0, l2 = table.rows[i].cells.length; j < l2; j++) {
result.push(table.rows[i].cells[j].innerText);
}
}
return result.join(',');
}
You could try this:
1) Add the existing code to a function so that you can pass in the column parameter.
2) tr.cells[0]
should be changed to tr.cells[col]
using the passed-in parameter.
3) change innerText
to innerHTML
as innerText doesn't work on some browsers.
function getCol(col) {
var s = '';
for (var i = 0; i < l; i++) {
var tr = tab.rows[i];
var cll = tr.cells[col];
s += ' ' + cll.innerHTML;
}
return s;
}
console.log(getCol(1)) // 222 in my example
Fiddle
tab.rows.length;
?? – Grijesh Chauhan Commented Feb 28, 2014 at 14:00cells[1]
- there is probably an empty column that you are missing. – tucuxi Commented Feb 28, 2014 at 14:01