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Dynamic string cutting

Okay, so I have a filepath with a variable prefix...
C:\Users\susan ivey\Documents\VKS Projects\secc-electron\src\views\main.jade
... now this path will be different for whatever computer I'm working on...
is there a way to traverse the string up to say 'secc-electron\', and drop it and everything before it while preserving the rest of it? I'm familiar with converting strings to arrays to manipulate elements contained within delimiters, but this is a problem that I have yet to come up with an answer to... would there be some sort of regex solution instead? I'm not that great with regex so I wouldn't know where to begin...

What you probably want is to do a split (with regex or not):
Here's an example:
var paragraph = 'C:\\Users\\susan ivey\\Documents\\VKS Projects\\secc-electron\\src\\views\\main.jade';
var splittedString = paragraph.split("secc-electron"); // returns an array of 2 element containing "C:\\Users\\susan ivey\\Documents\\VKS Projects\\" as the first element and "\\src\\views\\main.jade" as the 2nd element
console.log(splittedString[1]);
You can have a look at this https://www.w3schools.com/jsref/jsref_split.asp to learn more about this function.

With Regex you can do:
var myPath = 'C:\Users\susan ivey\Documents\VKS Projects\secc-electron\src\views\main.jade'
var relativePath = myPath.replace(/.*(?=secc-electron)/, '');
The Regex is:
.*(?=secc-electron)
It matches any characters up to 'secc-electron'. When calling replace it will return the last part of the path.

You can split the string at a certain point, then return the second part of the resulting array:
var string = "C:\Users\susan ivey\Documents\VKS Projects\secc-electron\src\views\main.jade"
console.log('string is: ', string)
var newArray = string.split("secc-electron")
console.log('newArray is: ', newArray)
console.log('newArray[1] is: ', newArray[1])

Alternatively you could use path.parse(path); https://nodejs.org/api/path.html#path_path_parse_path and retrieve the parts that you are interested in from the object that gets returned.

how to replace part of part of string in javascript

I have two GUIDs. I am looking for to replace c013d94e from 1st guid with cd11d94e of second guid in Javascipt.
I checked javascript replace() method but not sure how i can use it with my specific case.
c013d94e-3210-e511-82ec-303a64efb676 - 1st Guid
cd11d94e-3210-e511-82ec-303a64efb676 - 2nd Guid
Following is my code where i am trying to do it
for(var i=0; i < response[1].length;i++)
angular.forEach($scope.studentPermissions[i][0].Children, function (subject) {
string 1stGuid= response[1].data[i].Id; // it contains cd11d94e-3210-e511-82ec-303a64efb676
subject.Id = // it contains c013d94e-3210-e511-82ec-303a64efb676
});

replace takes 2 parameters, the first is the string to search for and the second is the replacement string. It doesn't modify the original string, it simply returns a new string with the value replaced.
You can perform your replace like this:
var guid = 'c013d94e-3210-e511-82ec-303a64efb676';
guid = guid.replace('c013d94e', 'cd11d94e');
console.log(guid); // 'cd11d94e-3210-e511-82ec-303a64efb676'

#Jamen. Yes the other part of 1st string will always be same. How can i use concatenate?
You don't even need to use replace then? Just make a brand new string:
var guid = "cd11d94e-3210-e511-82ec-303a64efb676";
But, to actually answer the question in the title:
var input = "c013d94e-3210-e511-82ec-303a64efb676";
var output = input.replace("c013d94e", "cd11d94e");
console.log(output); // cd11d94e-3210-e511-82ec-303a64efb676
But like I said, in your situation this shouldn't be necessary, based on the quote.

Remove plus sign (+) in URL query string

I am trying get the string in the following URL to display on my webpage.
http://example.com?ks4day=Friday+September+13th
EDIT: The date in the URL will change from person to person as it's merged in by my CRM program.
I can get it to display on my webpage using the code below, the problem is the plus signs (+) come through as well.
eg. Friday+September+13th
What I need it to do is replace the plus signs (+) with spaces so it looks like this:
eg. Friday September 13th
I'm new to this so I'm having some trouble working it out.
Any help would be appreciated.
This is the code i'm using in a .js file
function qs(search_for) {
var query = window.location.search.substring(1);
var parms = query.split('&');
for (var i=0; i<parms.length; i++) {
var pos = parms[i].indexOf('=');
if (pos > 0 && search_for == parms[i].substring(0,pos)) {
return parms[i].substring(pos+1);;
}
}
return "";
}
This is the code i'm using on my webpage to make it display
<script type="text/javascript">document.write(qs("ks4day"));</script>

Although Bibhu's answer will work for this one case, you'll need to add decodeURIComponent if you have encoded characters in your URI string. You also want to make sure you do the replace before the decode in case you have a legitimate + in your URI string (as %2B).
I believe this is the best general way to do it:
var x = qs("ks4day"); // 'Friday+September+13th'
x = x.replace(/\+/g, '%20'); // 'Friday%20September%2013th'
x = decodeURIComponent(x); // 'Friday September 13th'
Here's an example of when it might be useful:
var x = '1+%2B+1+%3D+2';
x = x.replace(/\+/g, '%20'); // '1%20%2B%201%20%3D%202'
x = decodeURIComponent(x); // '1 + 1 = 2'

You can use replace() for this purpose
var dateString = 'Friday+September+13th';
var s = dateString .replace(/\+/g, ' ');

Parsing strings using regex is often prone to so many errors. Thankfully all modern browsers provide URLSearchParams to handle params from url strings in a proper way:
var params = new URLSearchParams(window.location.search);
var value = params.get('ks4day');
// "Friday September 13th"
Ps: There is also a good polyfill for old browsers.

Have you tried https://www.npmjs.com/package/querystring ?
import { parse } from 'querystring';
parse('ks4day=Friday+September+13th')
returns
{ 'ks4day': 'Friday September 13th' }
Assuming you are using something like Webpack that knows how to process import statements

If that's what you are doing, the plus sign will not be the only one that is going to give you a hard time. The apostrophe ('), equals (=), plus (+) and basically anything not in the permitted URL characters (see Percent-encoding # Wikipedia) is going to get escaped.
You are most likely looking for the decodeURIComponent function.

JS Regex match string with $

I am trying to write something that would look at tweets and pull up info about stocks being mentioned in the tweet. People use $ to reference stock symbols on twitter but I cant escape the $.
I also dont want to match any price mention or anything like that so basically match $AAPL and not $1500
I was thinking it would be something like this
\b\$[a-zA-Z].*\b
if there are multiple matches id like to loop through them somehow so something like
while ((tweet = reg.exec(sym_pat)) !== null) {
//replace text with stock data.
}
This expression gives me an unexpected illegal token error
var symbol_pat = new RegExp(\b\$[a-z]*);
Thanks for the help if you want to see the next issue I ran into
Javascript AJAX scope inside of $.each Scope

Okay, you've stated that you want to replace the matches with their actual stock values. So, you need to get all of the matching elements (stock ticker names) and then for each match you're going to replace the it with the stock value.
The answer will "read" very similarly to that sentence.
Assume there's a tweet variable that is the contents of a particular tweet you're going to work on:
tweet.match(/\b\$[A-Za-z]+\b/g).forEach(function(match) {
// match looks like '$AAPL'
var tickerValue = lookUpTickerValue(match);
tweet.replace(match, tickerValue);
});
This is assuming you have some logic somewhere that will grab the ticker value for the given stock name and then replace it (it should probably return the original value if it can't find a match, so you don't mangle lovely tweets like "Barbara Streisand is $ATAN").

var symbol_pat = new RegExp('\\b\\$[a-z]+\\b','gi');
// or
var symbol_pat = /\b\$[a-z]+\b/gi;
Also, for some reason JS can not calculate the beginning of a word by \b, it just catches the one at the end.
EDIT: If you're replacing the stock symbols you can use the basic replace method by a function and replace that data with predefined values:
var symbol_pat = /(^|\s)(\$[a-z]+\b)/gi;
var stocks = {AAPL:1,ETC:2}
var str = '$aapl ssd $a a$s$etc $etc';
console.log(str);
str = str.replace(symbol_pat, function() {
var stk = arguments[2].substr(1).toUpperCase();
// assuming you want to replace $etc as well as $ETC by using
// the .toUpperCase() method
if (!stocks[stk]) return arguments[0];
return arguments[0].replace(arguments[2],stocks[stk]);
});
console.log(str);

Using javascript regex to translate a html

I would like to build my own translation function in javascript.
I already have a function language.lookup(key) which translates a word or expression:
var frenchHello = language.lookup('hello') //'bonjour'
Now I would like to write a function which takes a html string and translates it with my lookup function. In the html string I will have a special syntax for example #[translationkey] that will point out that this word should be translated.
This is the result I want:
var html = '<div><span>#[hello]</span><span>#[sir]</span>'
language.translate(html) //'<div><span>bonjour</span><span>monsieur</span>
How would I write language.translate?
My idea is to filter out my special syntax with regex and then run language.lookup on each key. Maybe with string replace or something.
I suck when it comes to regex and I've only come up with a very incomplete example but I include it anyway so maybe someone get the idea of what I am trying to do. Then if there is a better but complete different solution that is more than welcome.
var value = "#[hello], nice to see you.";
lookup = function(word){
return "bonjour";
};
var res = new RegExp( "\\b(hello)\\b", "gi" ).exec(value)
for (var c1 = 0; c1 < res.length; c1++){
value = value.replace(res[c1], lookup(res[c1]))
}
alert(value) //#[bonjour], nice to see you.
The regex should of course not filter out the word hello but the syntax and then collect the key by grouping or similar.
Can anyone help?

Just use String.replace method's ability to call function specified as second argument to generate replacement text and make a global replace using regexp matching your syntax:
var value = "#[hello], #[sir], nice to see you.";
lookup = function(full_match, word){
if(word == 'hello')
return "bonjour";
if(word == 'sir')
return "monsieur"
};
console.log(value.replace(/#\[(.+?)\]/gi, lookup))
Result:
bonjour, monsieur, nice to see you.
Of course when your replacement list gets bigger, you'd better use lookup object instead of series of ifs in lookup function, but you can really do whatever you want there.

You can try this to find all occurrences:
var re = new RegExp('#\\[([^\\]]+?)\\]', 'gi'),
str = '#[value1] plain text #[value2]',
match;
while (match = re.exec(str)) {
console.log(match);
}

You could use something like:
#\\[[^\\]]*\\]
Which matches the hash followed by an opening square bracket followed by zero or more characters NOT including the closing square bracket, followed by a closed square bracket.
Alternatively, perhaps it would be better to handle the translation at the server side (maybe even through your template engine) and send back to your client the translated response. Otherwise, (depending on the specific problem you are dealing with of course), you might end up sending a lot of data to the browser which might make your application respond slowly.
EDIT:
Here is a working piece of code:
var q="This #[ANIMAL1] was eaten by that #[ANIMAL2]";
var u = {"#[ANIMAL1]":"Lion","#[ANIMAL2]":"Frog"};
function insertAnimal(aString, lookup){
var res = (new RegExp("#\\[[^\\]]*\\]", "gi"))
while (m = res.exec(aString)){
aString = aString.replace(m, lookup[m])
}
return aString;
}
function main(){
alert(insertAnimal(q,u));
}
You can call the "main()" from an HTML document's body onload event

I can compare your requirement to 'resolving template texts within content'. If it is feasible to use Jquery , you should try Handlebars.js
.