Develop Reference

How do I replace string within quotes in javascript?

I have this in a javascript/jQuery string (This string is grabbed from an html ($('#shortcode')) elements value which could be changed if user clicks some buttons)
[csvtohtml_create include_rows="1-10"
debug_mode="no" source_type="visualizer_plugin" path="map"
source_files="bundeslander_staple.csv" include cols="1,2,4" exclude cols="3"]
In a textbox (named incl_sc) I have the value:
include cols="2,4"
I want to replace include_cols="1,2,4" from the above string with the value from the textbox.
so basically:
How do I replace include_cols values here? (include_cols="2,4" instead of include_cols="1,2,4") I'm great at many things but regex is not one of them. I guess regex is the thing to use here?
I'm trying this:
var s = $('#shortcode').html();
//I want to replace include cols="1,2,4" exclude cols="3"
//with include_cols="1,2" exclude_cols="3" for example
s.replace('/([include="])[^]*?\1/g', incl_sc.val() );
but I don't get any replacement at all (the string s is same string as $("#shortcode").html(). Obviously I'm doing something really dumb. Please help :-)

In short what you will need is
s.replace(/include cols="[^"]+"/g, incl_sc.val());
There were a couple problems with your code,
To use a regex with String.prototype.replace, you must pass a regex as the first argument, but you were actually passing a string.
This is a regex literal /regex/ while this isn't '/actually a string/'
In the text you supplied in your question include_cols is written as include cols (with a space)
And your regex was formed wrong. I recomend testing them in this website, where you can also learn more if you want.
The code above will replace the part include cols="1,2,3" by whatever is in the textarea, regardless of whats between the quotes (as long it doesn't contain another quote).

First of all I think you need to remove the quotes and fix a little bit the regex.
const r = /(include_cols=\")(.*)(\")/g;
s.replace(r, `$1${incl_sc.val()}$3`)
Basically, I group the first and last part in order to include them at the end of the replacement. You can also avoid create the first and last group and put it literally in the last argument of the replace function, like this:
const r = /include_cols=\"(.*)\"/g;
s.replace(r, `include_cols="${incl_sc.val()}"`)

Why would the replace with regex not work even though the regex does?

There may be a very simple answer to this, probably because of my familiarity (or possibly lack thereof) of the replace method and how it works with regex.
Let's say I have the following string: abcdefHellowxyz
I just want to strip the first six characters and the last four, to return Hello, using regex... Yes, I know there may be other ways, but I'm trying to explore the boundaries of what these methods are capable of doing...
Anyway, I've tinkered on http://regex101.com and got the following Regex worked out:
/^(.{6}).+(.{4})$/
Which seems to pass the string well and shows that abcdef is captured as group 1, and wxyz captured as group 2. But when I try to run the following:
"abcdefHellowxyz".replace(/^(.{6}).+(.{4})$/,"")
to replace those captured groups with "" I receive an empty string as my final output... Am I doing something wrong with this syntax? And if so, how does one correct it, keeping my original stance on wanting to use Regex in this manner...
Thanks so much everyone in advance...

The code below works well as you wish
"abcdefHellowxyz".replace(/^.{6}(.+).{4}$/,"$1")
I think that only use ()to capture the text you want, and in the second parameter of replace(), you can use $1 $2 ... to represent the group1 group2.
Also you can pass a function to the second parameter of replace,and transform the captured text to whatever you want in this function.
For more detail, as #Akxe recommend , you can find document on https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replace.

You are replacing any substring that matches /^(.{6}).+(.{4})$/, with this line of code:
"abcdefHellowxyz".replace(/^(.{6}).+(.{4})$/,"")
The regex matches the whole string "abcdefHellowxyz"; thus, the whole string is replaced. Instead, if you are strictly stripping by the lengths of the extraneous substrings, you could simply use substring or substr.
Edit
The answer you're probably looking for is capturing the middle token, instead of the outer ones:
var str = "abcdefHellowxyz";
var matches = str.match(/^.{6}(.+).{4}$/);
str = matches[1]; // index 0 is entire match
console.log(str);

How to replace string in javascript?

I have a string which is like
var test="clientNumber=123,TestSubject=Tom";
I need to replace Tom with Mary. Tom is entered by the user and could be anything but i need to make it Mary while processing . Also clientNumber & TestSubject could be in any order in the string.
Thanks

You seem to want to use a regular expression, for example
test = test.replace(/(TestSubject=)[^,]*/, '$1Mary')
The code I give replaces everything between "TestSubject=" and the end of string or the next comma.
This changes
"clientNumber=123,TestSubject=Tom" into "clientNumber=123,TestSubject=Mary"
and
"TestSubject=Tom,clientNumber=123" into "TestSubject=Mary,clientNumber=123"

if pathname starts with, as well as contains . Regex

I am trying to test the pathname of the url, checking if pathname starts with privmsg as well as contains one of the words in the selection. And my quantifier is selecting that at least one word must be found.
New RegExp thanks to one of the answers and I extended it more.
var post = /(^\/privmsg\?).+(post|reply){1}(.*)?/;
My urls will look like
/privmsg?mode=post
/privmsg?mode=reply
/privmsg?mode=reply&p=2 //another way
Though we have other modes that I do not want. I need to just get the constant url beginning with privmsg and having at least post or reply in it. Can someone explain what is wrong with my regex string and if I used the quantifier incorrectly.
Problem now is that it is still coming out false...

You need to allow for arbitrary characters between ? and (post|reply) (i.e. mode=). E.g.:
var post = /^\/privmsg\?.+(post|reply){1}/g;
\/
|match any sequence of|
|1 or more characters |

You miss to include something for mode=.
With your regex you will match strings like /privmsg?post.
So alter your regex to include mode=:
^\/privmsg\?.*(post|reply)$

Omitting special characters from the string using Jquery

I have to implement some type of pixel for analytic and it requires passing a session Id in the url string. My sessionID contains special characters. It looks something like this BFhGlzT6FBkDr2Zndp0!-1309
I need to remove the (-!) characters from this string, how do I achieve this using jquery? I need to make sure jquery remove those characters before it render otherwise it will not report a visit to analytic.
Guys thanks your help but maybe I need to explain bit further, my pixel code look some what like this "
img src="https://sometime.com/png?org_id=k8vif92&session_
id=T6PtTyRSqhGPYBhp84frwth67n6fL7wcLBFhGlzT6FBkDr2Zndp0!-130901808!1319637471144&m=2&m=2" alt="">
Before this pixel fire off, I need to replace the character in the sessionId string to remove !- and keep in mind session id will change every time there is a new session. I need a code that is generic so it works no matter what session id is, it needs to delete special characters from it.

Try using .replace:
var token = "BFhGlzT6FBkDr2Zndp0!-1309";
token.replace(/[^A-Za-z0-9]/g, "");
this will remove any character that's not a letter or number. More concisely:
token.replace(/\W/g, "");
(this won't replace underscores)

Black-listing ! and - (fiddle):
var url = "BFhGlzT6FBkDr2Zndp0!-1309";
document.write(url.replace(/[!\-]/g,""));
White-listing alpha-numeric (fiddle):
var url = "BFhGlzT6FBkDr2Zndp0!-1309";
document.write(url.replace(/[^a-z0-9]/ig,""));

var str = "BFhGlzT6FBkDr2Zndp0!-1309".replace("!-","");
fiddle: http://jsfiddle.net/neilheinrich/eYCjX/

Define a regular expression character set that contains all the allowed characters. For example, yours might look like /[a-zA-Z0-9]/. Now invert it with the complementary character set [^a-zA-Z0-9] and remove all those characters with the String.replace method.
mystring = mystring.replace(/[^a-zA-Z0-9]/g, "");

You dont need jquery for this. You can use javascript regex. See this jsfiddle
var code = "BFhGlzT6FBkDr2Zndp0!-1309";
code = code.replace(/[!-]/g,"");
alert(code);