Develop Reference

How to update all child IDs using plain JavaScript

I have a JavaScript function called resetIndex. It works fine but I want to reset all child IDs. How can I do this? Is there any method like firstChild and lastChild?
I'm new with JavaScript. Can anyone help?
I have following function:
function resetIndex(delId) {
for (var i = delId + 1; i < count; i++) {
var currentElement = document.getElementById(i);
currentElement.id = i - 1;
var update = currentElement.childNodes;
update.setAttribute('id', 'deleteLink(' + currentElement.id + ')');
}
count--;
}

You can use
node.children[0]
to get the first one, and
node.children[node.children.length - 1]
to get the last one.
Make sure to check if they exist, first.
To do something to all child-nodes, you can use a for-loop, like
for(let a = 0; a < node.children.length; a++) {
node.children[a].id = "my-new-id";
}

Javascript keep getting undefined after function - prompt

So I`m working ona simple JS code. We just started to learn about functions.
I need to make a function named "printStars".
I need to take a number from the user and accourding that number print "*".
This is what I did:
<script>
function printStars()
{
var n = Number(prompt("Insert number of stars:","0.."));
for (i = 0; i < n; i++)
{
document.write("*");
}
}
var stars = printStars();
document.write(stars);
</script>
In the end I get my result with a minus of getting "undefined".
I would love to get some help, and an explanation why is keep happening.
Thanks guys!

jsfiddle demo
function printStars(){
var n = prompt("Insert number of stars:","0..");
var stars='';
for (i = 0; i < n; i++){
stars+='*';
}
$('body').html(stars) //jsfiddle does not allow document.write()
//document.write(stars);
}
//call the function
printStars();

You don't need this
document.write(stars);
You just need this:
// This will make you function to be evaluated and
// the code in your function will be executed.
printStars();
function printStars()
{
var n = Number(prompt("Insert number of stars:","0.."));
for (i = 0; i < n; i++)
{
document.write("*");
}
}
printStars();

Custom function for Google Spreadsheet always return the same result

I am trying to build a simple script to work with a Google Spreadsheet that looks like this:
It shows me which of my clients use which modules of each layer. Each client may use how many modules he wants to.
What I need to do is count how many clients have all the modules installed (or the three layers, it's the same).
I've tried to do this using the built-in functions but have not succeed.
Now I'm trying to do my own function, that looks like this:
function countTotalModByClient(values) {
var quantMod=0;
var quantClient=0;
for (var i=0; i<values.length; i++) {
for(var j=0; j<values.length; j++) {
if(values[i][j]=="X") {
quantMod++;
}
}
if(quantMod==15) { // total number of modules
quantClient++;
}
quantMod=0;
}
return quantClient;
}
But it always return the same result: 0.
At my sheet, I'm calling the function like this: =countTotalModByClient(B3:P6)
P.S.: Sorry about the magic number in the code, I´ll fix this. =)

This should be possible with a standard formula (although maybe a little complex).
=countif(ArrayFormula(MMULT(--(B3:P6="X"), transpose(column(B3:P2)^0))), 15)
should return the number of clients with a count of 15 in their row..
Can you check if that works ?
Or if you prefer a custom function, give this a try:
function countTotalModByClient(values) {
var quantClient = 0;
for (var i = 0; i < values.length; i++) {
if (values[i].countItem("X") === 15) quantClient += 1;
}
return quantClient;
}
Array.prototype.countItem = function (item) {
var counts = {};
for (var i = 0; i < this.length; i++) {
var num = this[i];
counts[num] = counts[num] ? counts[num] + 1 : 1;
}
return counts[item] || 0;
}
Example spreadsheet

Using for loop to get for specific iteration result in javascript

I need help in somewhere in javascript
var obj = jQuery.parseJSON(data.d);
This ajax call result returns some data (around 31).
Here is an example:
obj[0] = 10, obj[1]=20 ,obj[2]=30 , obj[4]=21,obj[5]=16,obj[6]=54 here I want to get value of
obj[0] and ob[4] using for loop . And I also need to do this for obj[10] and obj[14] the difference will be 5 between the i values .
Any idea or help?

You can do something like this (a pseudo code)
int i = 0;
while(i < 31)
{
print(i);
i = i + 4;
}

If i understood, you want to skip 5 on each step:
var array = 'abcdefghijklmnopqrstuvwxyz'.split(''); // something that generates an array just to show an example
var i = 0;
for (; i < array.length;) {
console.log(i, array[i]);
i += 5;
}
see fiddle

var iterator=0;
for (i = 0; i < obj.length; i++) {
if(i == iterator){
alert(obj[iterator]);
iterator= iterator + 4;
}
}

Why this JS function does't not work when it calls by selenium.getEval()

Below js function is working well in html page. But when i put it into selenium.getEval in RC to wonder to get return value j. It cannot work, also without any error. Do i miss some function call format? Thanks in advance!!!
function GetTableRow()
{
var table;
var ctext = "bb";
var cname = "mps_tableborder";
var col = 0;
var j;
for (i = 0; i < document.getElementsByTagName("table").length; i++) {
if (cname==document.getElementsByTagName("table")[i].className) {
table = document.getElementsByTagName("table")[i];
break;
}
}
for (j = 0; j < table.rows.length; j++){
if (ctext == table.rows[j].cells[col].innerText){
break;
}
}
return (j);
}

You can provide only the contents of method. Not the entire method. Try by removing the method starting [ function GetTableRow() { ] and method ending [ } ] and give it to getEval method and see what it returns! Ideally it should work fine.