string replace using a regex - javascript

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,'^')})

Related

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/'>

Regex to match number after string without the matching string

I'm trying to write a regex in javascript to match a series of numbers after a particular string without getting the string in result. So far, I have come up with this:
(?!smart_id=)[0-9]+
which is to be tested against strings like:
ksld8403smart_id=9034&kqwop
discid=783&smartid=83234&ansqw
fdsjfnfd3209sdf&smart_id=2102&hjg
but I'm getting both the numbers before and after smart_id. The tests need to be performed on https://regexr.com/
You can use regex along with array#map. Once you have matched result, you can array#split the result on = and get the value at the first index.
var str = `ksld8403smart_id=9034&kqwop
discid=783&smartid=83234&ansqw
fdsjfnfd3209sdf&smart_id=2102&hjg`;
console.log(str.match(/(smart_id=)(\d+)/g).map(matched => +matched.split('=')[1]));

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].

Replace .split() with .match() using regex in javascript

I'm having difficulties with constructing some regular expressions using Javascript.
What I need:
I have a string like: Woman|{Man|Boy} or {Girl|Woman}|Man or Woman|Man etc.
I need to split this string by '|' separator, but I don't want it to be split inside curly brackets.
Examples of strings and desired results:
// Expample 1
string: 'Woman|{Man|Boy}'
result: [0] = 'Woman', [1] = '{Man|Boy}'
// Example 2
string '{Woman|Girl}|{Man|Boy}'
result: [0] = '{Woman|Girl}', [1] = '{Man|Boy}'
I can't change "|" symbol to another inside the brackets because the given strings are the result of a recursive function. For example, the original string could be
'Nature|Computers|{{Girls|Women}|{Boys|Men}}'
try this:
var reg=/\|(?![^{}]+})/g;
Example results:
var a = 'Woman|{Man|Boy}';
var b = '{Woman|Girl}|{Man|Boy}';
a.split(reg)
["Woman", "{Man|Boy}"]
b.split(reg)
["{Woman|Girl}", "{Man|Boy}"]
for your another question:
"Now I have another, but a bit similar problem. I need to parse all containers from the string. Syntax of the each container is {sometrash}. The problem is that container can contain another containers, but I need to parse only "the most relative" container. mystring.match(/\{+.+?\}+/gi); which I use doesn't work correctly. Could you correct this regex, please? "
you can use this regex:
var reg=/\{[^{}]+\}/g;
Example results:
var a = 'Nature|Computers|{{Girls|Women}|{Boys|Men}}';
a.match(reg)
["{Girls|Women}", "{Boys|Men}"]
You can use
.match(/[^|]+|\{[^}]*\}/g)
to match those. However, if you have a nesting of arbitrary depth then you'll need to use a parser, [javascript] regex won't be capable of doing that.
Test this:
([a-zA-Z0-9]*\|[a-zA-Z0-9]*)|{[a-zA-Z0-9]*\|[a-zA-Z0-9]*}

assign matched values from jquery regex match to string variable

I am doing it wrong. I know.
I want to assign the matched text that is the result of a regex to a string var.
basically the regex is supposed to pull out anything in between two colons
so blah:xx:blahdeeblah
would result in xx
var matchedString= $(current).match('[^.:]+):(.*?):([^.:]+');
alert(matchedString);
I am looking to get this to put the xx in my matchedString variable.
I checked the jquery docs and they say that match should return an array. (string char array?)
When I run this nothing happens, No errors in the console but I tested the regex and it works outside of js. I am starting to think I am just doing the regex wrong or I am completely not getting how the match function works altogether
I checked the jquery docs and they say that match should return an array.
No such method exists for jQuery. match is a standard javascript method of a string. So using your example, this might be
var str = "blah:xx:blahdeeblah";
var matchedString = str.match(/([^.:]+):(.*?):([^.:]+)/);
alert(matchedString[2]);
// -> "xx"
However, you really don't need a regular expression for this. You can use another string method, split() to divide the string into an array of strings using a separator:
var str = "blah:xx:blahdeeblah";
var matchedString = str.split(":"); // split on the : character
alert(matchedString[1]);
// -> "xx"
String.match
String.split

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