Develop Reference

Regular Express for Javascript - Contain a specific word in the beginning after get any character until a certain character comes

I need a certain type of regular expression where I need list of special type of strings from a string. Example input:
str = 'this is extra data which i do not need /type/123456/weqweqweqweqw/ these are more extra data which i dont need /'
Result needed:
/type/123456/weqweqweqweqw/
Here the /type/ string will be constant and the remaining will be dynamic i.e. 123456/weqweqweqweqw and the last string will be /.
I tried:
var myRe = /\/type\/(.*)\//g
But this matches everything from /type/ to the end of the string.

Instead of repeating ., which will match anything, repeat anything but a space via \S+, so that only the URL part of the string will be matched:
const str = 'this is extra data which i do not need /type/123456/weqweqweqweqw/ these are more extra data which i dont need /';
console.log(str.match(/\/type\S+/));

It's tagged Python, so here is a solution:
import re
re.search(r"/type/[^/]*/[^/]*/",str)
Out: <_sre.SRE_Match object; span=(39, 66), match='/type/123456/weqweqweqweqw/'>

why isn't this javascript regex split function working?

I'm trying to split a string by either three or more pound signs or three or more spaces.
I'm using a function that looks like this:
var produktDaten = dataMatch[0].replace(/\x03/g, '').trim().split('/[#\s]/{3,}');
console.log(produktDaten + ' is the data');
I need to clean the data up a bit, hence the replace and trim.
The output I'm getting looks like this:
##########################################################################MA-KF6###Beckhoff###EL1808 BECK.EL1808###MA-KF7###Beckhoff###EL1808 BECK.EL1808###MA-KF12###Beckhoff###EL1808 BECK.EL1808###MA-KF13###Beckhoff###EL1808 BECK.EL1808###MA-KF14###Beckhoff###EL1808 BECK.EL1808###MA-KF15###Beckhoff###EL1808 BECK.EL1808###MA-KF16###Beckhoff###EL1808 BECK.EL1808###MA-KF19###Beckhoff###EL1808 BECK.EL1808 is the data
How is this possible? Irrespective of the input, shouldn't the pound and multiple spaces be deleted by the split?

You passed a string to the split, the input string does not contain that string. I think you wanted to use
/[#\s]{3,}/
like here:
var produktDaten = "##########################################################################MA-KF6###Beckhoff###EL1808 BECK.EL1808###MA-KF7###Beckhoff###EL1808 BECK.EL1808###MA-KF12###Beckhoff###EL1808 BECK.EL1808###MA-KF13###Beckhoff###EL1808 BECK.EL1808###MA-KF14###Beckhoff###EL1808 BECK.EL1808###MA-KF15###Beckhoff###EL1808 BECK.EL1808###MA-KF16###Beckhoff###EL1808 BECK.EL1808###MA-KF19###Beckhoff###EL1808 BECK.EL1808";
console.log(produktDaten.replace(/\x03/g, '').trim().split(/[#\s]{3,}/));
This /[#\s]{3,}/ regex matches 3 or more chars that are either # or whitespace.
NOTE: just removing ' around it won't fix the issue since you are using an unescaped / and quantify it. You actually need to quantify the character class, [#\s].

Remove the javascript object variable name text from json code

I have a String variable that stores the literal text of a JavaScript object:
String jsString = "mainData = {"name":"John", "id":"12345"}"
Is there a JSON method (or any method) in Java that will remove the "mainData = " part of the string in order to leave only the JavaScript data? Something like this:
newString = someMethod(jsString);
JSONObject jsonObject = new JSONObject(newString); //newString = "{"name":"John", "id":"12345"}"

There's String#replaceFirst:
jsString = jsString.replaceFirst("^[^{]+", "");
Live Example
That will remove any characters as the start of the string prior to the first {. It makes the assumption that the string contains JSON where the outermost thing is an object (as opposed to an array or just a value), although it could readily be tweaked not to make that assumption. For instance, this version:
jsString = jsString.replaceFirst("^\\s*[A-Za-z0-9_$]+\\s*=\\s*", "");
Live Example
That removes a series of letters, numbers, _, or $, optionally surrounded by whitespace, and a following =, possibly followed by whitespace, at the beginning of the string. Now, that's not a complete list of valid JavaScript identifier characters (that list is long), but you get the idea.

string replace using a regex

I have a string after Json.stringify in javascript using node. I wanted to replace the text in the string which starts with 'ab' then followed by some numbers(atleast one digit), with 'ab^^^^^^' where the number of '^' s should be equal to the number of digits after ab. The text starting with ab can occur atleast once, In this example it occurs twice. I need help in regex and replacing the string
string - in this, text starting with ab occurs twice.
var str = JSON.stringify({"abc":{"idcardno":"ertyuiop","form":{"somestring":"This string:\n- can have multiple \nab12345ab5677\n","flag":"true","flag2":"false"},"anothertext":"samplestring","numbetstr":"7"}});
after the regex replace it should be like this
{"abc":{"idcardno":"ertyuiop","form":{"somestring":"This string:\n- can have multiple \na^^^^^ab^^^^\n","flag":"true","flag2":"false"},"anothertext":"samplestring","numbetstr":"7"}}
Edit
As per the post below the below will be the contents of obj.abc.form.string, coming in multiple lines. How do I do the regex(above mentioned) replace of this object?
This string:
- can have multiple
ab12345ab56778

Don't process stringifed JSON with regexp. Process the JavaScript object itself, then stringify. In your case, assuming obj is the input:
obj.abc.form.somestring = transform(obj.abc.form.somestring);
str = JSON.stringify(obj);
where transform is a regexp/replace making the transformation you want.

#torazaburo is right, it's a bad practice to manipulate JSON directly. Once you get ahold of the string in obj.abc.form.somestring, though, you can use replace, passing a function:
str.replace(/ab\d+/g, function(match) {return match.replace(/\d/g,'^')})

Splitting string with javascript using '>' character

I acknowledge that this question has probably been asked so many times before and I have tried searching all over StackOverflow for a solution, but so far nothing has worked for me.
I want to split a string but it's not working properly and spitting out individual characters as each item in an array. The string I have from my CMS uses ">" characters to separate and I am using regEx to replace the 'greater than' symbol - with a comma, which works. Sourced this solution from Regex that detects greater than ">" and less than "<" in a string
However, the arrays remain incorrectly formed, like the split() function does not even work:
var myString = "TEST Public Libraries Connect > News Blog > A new item"
var regEx = /<|>/g;
var myNewString = (myString.replace(regEx,","))
alert(myNewString);
myNewString.split(",");
alert(myNewString[0]);
alert(myNewString[1]);
alert(myNewString[2]);
I've put it up in a Fiddle as well, just confused as to why the split won't work properly. Is it because there is spaces in the string?

This should work:
var myNewString = myString.split(">");
https://jsfiddle.net/2j56cva0/3/
In your fiddle, you were splitting myNewString instead of the actual string.

myNewString.split(",");
You need to assign the result of the split to something. It does not just change the string itself into an array.
var parts = myNewString.split(",");