Develop Reference

document.getElementById("id").value , change id by adding a variable to it

function totalCost(obj,a){
var price = document.getElementById("price").value;
}
I want to create a new id adding variable a. If a =1, then the next id will be price1. How can I do it?

You can use Template Literals which allows embedded expressions:
function totalCost(obj,a){
var price = document.getElementById(`price${a}`).value;
}
OR: Using String Concatenation (if browser is yet to support Template Literals)
function totalCost(obj,a){
var price = document.getElementById('price' + a).value;
}

function totalCost(obj,a)
{
var price = document.getElementById("price"+a).value;
}
this solution is working fine .

Replace different Values in String?

I have a string which looks like this: (id:561644cdb40fbe0100247dd7:q) (id:56165d8a79c8c40100adbdb6:q) and I need to replace the different id's with different values. I already have the id's in a variable and trying to loop through with something like this var mailId = "(id:" + rplcId + ":q)"; But If I use the replace() function it doesnt work...Any other suggestions?

You can select the id with:
"(id:56165d8a79c8c40100adbdb6:q)".split(":")[1]

var id = "(id:561644cdb40fbe0100247dd7:q)";
var idArr = id.split(":");
idArr[1] = newId; //56165d8a79c8c40100adbdb6
var mailId = idArr[0]+idArr[1]+idArr[2];
and please provide your full code

Capturing variable names from a select

In the back end I have written some code that reads through a file and outputs to a list of JavaScript arrays for example, the page will see:
<script>
var peanuts = ["1","s","g","3","n"];
var cashewNuts = ["d","a","f","d","n"];
var PecanNuts = ["6","m","3","x","m"];
var BrazilNuts = ["j","n","7","v","s"];
var goingNuts = ["a","e","7","m","y"];
</script>
I then want to use an array based on the value of a somewhere else in that page.
So for example:
if($('select').val()===0){
alert(firstArray[1]);
}
My issue is that the variable names are decided on what is contained in the read file, I can't know this information. Is there a way to say for example
//collect the value from the select and assign it to a var
var varN = $('select').val();
//then collect another variable that has the variable name that
//equals the value of the 'varN'
I know this seems horrendous but unfortunately based on what I need to do, it is what I need to do :(

Yes. If for example your vars are in the global scope, you can do
var val = window[varN][0]; to get peanuts:1
If you do
var nuts = {
peanuts : ["1","s","g","3","n"],
cashewNuts : ["d","a","f","d","n"],
PecanNuts : ["6","m","3","x","m"],
BrazilNuts : ["j","n","7","v","s"],
goingNuts : ["a","e","7","m","y"]
}
then you can use
var val = nuts[varN][0];

If the variables are declared directly in <script>, you can use window[varN].

jQuery, Looping through paragraphs and getting text

So basically with jQuery, I am trying to loop through 3 paragraphs containing tweets. The 3 paragraphs are all of class .tweet-text
For some reason, in the following code, $test2 will be set properly to the first tweet's text, but in the each loop, the js crashes whenver i try to set str. Why is this?
var $tweets = $(".sidebar-tweet .tweet-text");
var $test2 = $tweets.text();
alert($test2);
$tweets.each(function(i, $tweet){
var str = $tweet.text();
alert(str);
});
I've been trying to debug this with Firebug but to no avail. Thanks for the help.

var $tweets = $(".sidebar-tweet .tweet-text");
$tweets.each(function(i, current){
var str = $(current).text();
alert(str);
});
The issue was that the current object is not by defalt a jquery object, you must wrap it $(current) ... to use the jquery methods

try this instead
var str = $(this).text();

Because $tweet will be a regular javascript object, not a jQuery object. You'll need to wrap it like:
var str = $($tweet).text();

The second argument to the .each method is not a jquery object, but the actual DOM element.
So you need to wrap it in jQuery again..
var $tweets = $(".sidebar-tweet .tweet-text");
var $test2 = $tweets.text();
alert($test2);
$tweets.each(function(i, tweet){
var str = $(tweet).text();
alert(str);
});
demo: http://jsfiddle.net/gaby/xjmZy/

remove specific text from variable - jquery

I have a variable in my script containing data test/test1. The part test/ is already stored in another variable. I want to remove test/ from the previous variable and want to store remaining part in another variable. how can I do this??
Thanks in advance...:)
blasteralfred

In your case, x/y:
var success = myString.split('/')[1]
You split the string by /, giving you ['x', 'y']. Then, you only need to target the second element (zero-indexed of course.)
Edit: For a more general case, "notWantedwanted":
var success = myString.replace(notWantedString, '');
Where notWantedString is equal to what you want to get rid of; in this particular case, "notWanted".

If your requirement is as straightforward as it sounds from your description, then this will do it:
var a = "test/test1";
var result = a.split("/")[1];
If your prefix is always the same (test/) and you want to just strip that, then:
var result = a.substring(5);
And if your prefix varies but is always terminated with a /, then:
var result = a.substring(a.indexOf("/") + 1);

To split at the first occurence of "/":
var oldstring = "test/test1";
var newstring = oldstring.substring(oldstring.indexOf("/")+1);
There are many other ways to do this, the other answers work fine too.

Have your pick:
JavaScript replace() function.
var data = "test/test1";
data = data.replace(/data/gi, 'test/');
Or:
var data = "test/test1";
var dataArray = data.split('/');
var data1 = dataArray[0];
var data2 = dataArray[1];