Just wondering...

[DoomedLung]

I've been reading the DHTML Reference (2nd edt.) book by Danny Goodman.
I've come to a point in the book where my scripting experience isn't
that great to understand some of the coding examples and was just
wondering if anyone could help.

I'm at chapter 5 section 'Dynamic Tables' this is the example I'm a
little confused with...

function drawTable(tbody ) {
var tr, td, i, j, oneRecord;
tbody = document.getEle mentById(tbody) ;
// node tree
var data = xDoc.getElement sByTagName("sea son")[0];
// for td class attributes
var classes = ["ctr","","","", "ctr"];
for (i = 0; i < data.childNodes .length; i++) {
// use only 1st level element nodes
if (data.childNode s[i].nodeType == 1) {
// one bowl record
oneRecord = data.childNodes[i];

tr = tbody.insertRow (tbody.rows.len gth);

td = tr.insertCell(t r.cells.length) ;
td.setAttribute ("class",classe s[tr.cells.length-1]);
td.innerHTML =
oneRecord.getEl ementsByTagName ("number")[0].firstChild.nod eValue;

td = tr.insertCell(t r.cells.length) ;
td.setAttribute ("class",classe s[tr.cells.length-1]);
td.innerHTML =
oneRecord.getEl ementsByTagName ("year")[0].firstChild.nod eValue;

td = tr.insertCell(t r.cells.length) ;
td.setAttribute ("class",classe s[tr.cells.length-1]);
td.innerHTML =
oneRecord.getEl ementsByTagName ("winner")[0].firstChild.nod eValue;

td = tr.insertCell(t r.cells.length) ;
td.setAttribute ("class",classe s[tr.cells.length-1]);
td.innerHTML =
oneRecord.getEl ementsByTagName ("loser")[0].firstChild.nod eValue;

td = tr.insertCell(t r.cells.length) ;
td.setAttribute ("class",classe s[tr.cells.length-1]);
td.innerHTML =
oneRecord.getEl ementsByTagName ("winscore")[0].firstChild.nod eValue + "
- " +
oneRecord.getEl ementsByTagName ("losscore")[0].firstChild.nod eValue;
}
}
}

Obviously this function draws a table and fills the cells with content
from an XML doc this line from the function is where I'm getting
confused:

td.setAttribute ("class",classe s[tr.cells.length-1]);

Why is there a -1 in the Statement?

[peter.chase]

DoomedLung wrote:

I've been reading the DHTML Reference (2nd edt.) book by Danny Goodman.
I've come to a point in the book where my scripting experience isn't
that great to understand some of the coding examples and was just
wondering if anyone could help.

I'm at chapter 5 section 'Dynamic Tables' this is the example I'm a
little confused with...

function drawTable(tbody ) {
var tr, td, i, j, oneRecord;
tbody = document.getEle mentById(tbody) ;
// node tree
var data = xDoc.getElement sByTagName("sea son")[0];
// for td class attributes
var classes = ["ctr","","","", "ctr"];
for (i = 0; i < data.childNodes .length; i++) {
// use only 1st level element nodes
if (data.childNode s[i].nodeType == 1) {
// one bowl record
oneRecord = data.childNodes[i];

tr = tbody.insertRow (tbody.rows.len gth);

td = tr.insertCell(t r.cells.length) ;
td.setAttribute ("class",classe s[tr.cells.length-1]);
td.innerHTML =
oneRecord.getEl ementsByTagName ("number")[0].firstChild.nod eValue;

td = tr.insertCell(t r.cells.length) ;
td.setAttribute ("class",classe s[tr.cells.length-1]);
td.innerHTML =
oneRecord.getEl ementsByTagName ("year")[0].firstChild.nod eValue;

td = tr.insertCell(t r.cells.length) ;
td.setAttribute ("class",classe s[tr.cells.length-1]);
td.innerHTML =
oneRecord.getEl ementsByTagName ("winner")[0].firstChild.nod eValue;

td = tr.insertCell(t r.cells.length) ;
td.setAttribute ("class",classe s[tr.cells.length-1]);
td.innerHTML =
oneRecord.getEl ementsByTagName ("loser")[0].firstChild.nod eValue;

td = tr.insertCell(t r.cells.length) ;
td.setAttribute ("class",classe s[tr.cells.length-1]);
td.innerHTML =
oneRecord.getEl ementsByTagName ("winscore")[0].firstChild.nod eValue + "
- " +
oneRecord.getEl ementsByTagName ("losscore")[0].firstChild.nod eValue;
}
}
}

Obviously this function draws a table and fills the cells with content
from an XML doc this line from the function is where I'm getting
confused:

td.setAttribute ("class",classe s[tr.cells.length-1]);

Why is there a -1 in the Statement?

Because array indexes start at zero. He is getting the element of
"classes" that corresponds to the last cell of the row.

[DoomedLung]

Hey, thanks for your speedy rely! Makes sense now :)

Cheers