Develop Reference

Regex to find the best matching subsetof a word

I have a list of coma separated words like cooler,bestwishes,congrat. I want to use regex to find the best matching word in this list. e.g Congratulations or Congrats matches congrat in the above list.
I have tried the regex below but it only works if the word in regex is the subset.
const regex = /[^,]*congratulation[^,]*/g;
const str = `this,cart,open,best-wishes,congrat`;
let m;
while ((m = regex.exec(str)) !== null) {
// This is necessary to avoid infinite loops with zero-width matches
if (m.index === regex.lastIndex) {
regex.lastIndex++;
}
// The result can be accessed through the `m`-variable.
m.forEach((match, groupIndex) => {
console.log(`Found match, group ${groupIndex}: ${match}`);
});
}
Is this possible using regex ?

Instead of searching for the target word's substring in a list of words you can search list of words in target word. That will reduce complexity and make it easier.
let words = ["cool","bestwishes","congrat","greatjob","welldone","kudos","thumbsup","keeprocking","rock","congrats"];
let word = "keeprockingbuddy";
let match = getMatchingWords(words,word);
console.log(match); // ["keeprocking", "rock"]
match = getMatchingWords(words,"Congratulations");
console.log(match); // ["congrat"]
function getMatchingWords(words,target){
let ans = [];
words.forEach((w)=>{
let found = target.match(new RegExp(w,"i"));
if(found){
ans.push(w);
}
})
ans = ans.length ? ans:"not found";
return ans;
}
Hope it answers your question.

Regex for parsing multiple conditions for groups

I am trying to split string in 3 different parts with regex.
I can only get function parameters from string but i also want to other parts of the string
const regex = /(\(.*?\))+/g;
const sampleString = 'collection.products(take:12|skip:16)';
const result = sampleString.match(regex)
It gives me (take:12|skip:16)
But i also want to get collection and products
Expected result in match
collection
products
take:12|skip:16

Here, we can alter two expressions together:
(\w+)|\((.+?)\)
which group #1 would capture our desired words (\w+) and group #2 would capture the desired output in the brackets.
const regex = /(\w+)|\((.+?)\)/gm;
const str = `collection.products(take:12|skip:16)`;
let m;
while ((m = regex.exec(str)) !== null) {
// This is necessary to avoid infinite loops with zero-width matches
if (m.index === regex.lastIndex) {
regex.lastIndex++;
}
// The result can be accessed through the `m`-variable.
m.forEach((match, groupIndex) => {
console.log(`Found match, group ${groupIndex}: ${match}`);
});
}
Demo
RegEx Circuit
jex.im visualizes regular expressions:

You can split the string on . and (\(.*?\))+ and then use reduce to get values in desired format
const sampleString = 'collection.products(take:12|skip:16)';
const result = sampleString.split(/\.|(\(.*?\))+/).reduce((op,inp) => {
if(inp){
inp = inp.replace(/[)(]+/g,'')
op.push(inp)
}
return op
},[])
console.log(result)

This splits on what you want.
const sampleString = 'collection.products(take:12|skip:16)';
const result = sampleString.split(/[.()]*([^.()]+)[.()]*/).filter(function (el) {return el != "";});
console.log(result)

I need to write Regx for text field validation, which start with either 'iqn.yyyy-mm.com.' or 'eqn.'

I need to write Regx for text field validation, which start with either 'iqn.yyyy-mm.com.' or 'eqn.'
After this any number of character or numeric value is allowed
Here 'yyyy-mm' is year and month.

If we are just validating the year and month and before and after chars are OK, then this expression might work:
.+\.[\d]{4}-[\d]{2}\..+
If we wish to add more constraints, we can surely do so by modifying these two .+ in the start and end of string. We can also add start and end chars, if necessary.
const regex = /.+\.[\d]{4}-[\d]{2}\..+/gm;
const str = `iqn.2019-10.com
eqn.2019-10.com
eqn.209-10.com`;
let m;
while ((m = regex.exec(str)) !== null) {
// This is necessary to avoid infinite loops with zero-width matches
if (m.index === regex.lastIndex) {
regex.lastIndex++;
}
// The result can be accessed through the `m`-variable.
m.forEach((match, groupIndex) => {
console.log(`Found match, group ${groupIndex}: ${match}`);
});
}
DEMO
RegEx
If this expression wasn't desired, it can be modified/changed in regex101.com.
RegEx Circuit
jex.im visualizes regular expressions:

If you mean is "either 'iqn.yyyy-mm.com.' or 'eqn.'":
pattern = new RegExp('/^(iqn\.\d{4}-\d{2}\.com\.)|(eqn\.)$/');
var str = 'iqn.2019-05.com.';
pattern.test(str); // -> true
var str = 'eqn';
pattern.test(str); // -> true
var str = 'anything else';
pattern.test(str); // -> false
or, if you mean is "either 'iqn.yyyy-mm.com.' or 'eqn.yyyy-mm.com.'":
pattern = new RegExp('/^[ie]qn\.\d{4}-\d{2}\.com\.$/');
var str = 'iqn.2019-05.com.';
pattern.test(str); // -> true
var str = 'eqn.2019-05.com.';
pattern.test(str); // -> true
var str = 'anything else';
pattern.test(str); // -> false

I think this should work :
^[ie]qn\.(?:\d{4}-\d{2}\.\w{2,6})?\.?.+$
Regex101 Link here : Link Here

Getting string parameters using regex

I'm trying to get a regex that can extract data from
BAYARPLN ke 116160029354, SUKSES. Hrg: 84.822. SN: TGK IMUM M SAMIN/R1/450/MAR,APR/Rp.89222/Adm6000/977-1071/047421CA414149E5CEC5. Saldo: 7
and I want to find this value like this...
977-1071
I tried to using parameter regex link this
"/(Adm6000)([^\7]+)/"
But I cant find the string regex 977-1071. Can I ask for help for this?

Did you try like this? see regex https://regex101.com/r/tccJ42/1
const regex = /\d+\-\d+/g; //use \d{3}\-\d{4} if you've digit limit
const str = `BAYARPLN ke 116160029354, SUKSES. Hrg: 84.822. SN: TGK IMUM M SAMIN/R1/450/MAR,APR/Rp.89222/Adm6000/977-1071/047421CA414149E5CEC5. Saldo: 7`;
let m;
while ((m = regex.exec(str)) !== null) {
// This is necessary to avoid infinite loops with zero-width matches
if (m.index === regex.lastIndex) {
regex.lastIndex++;
}
// The result can be accessed through the `m`-variable.
m.forEach((match, groupIndex) => {
console.log(`Found match, group ${groupIndex}: ${match}`);
});
}

If you want to match 977-1071 after /Adm6000/ you could first match /Adm6000/ and then capture in a group not a forward slash one or more times ([^/]+)
\/Adm6000\/([^/]+)
Your value 977-1071 will be in captured group 1:
const regex = /Adm6000\/([^/]+)/;
const str = `BAYARPLN ke 116160029354, SUKSES. Hrg: 84.822. SN: TGK IMUM M SAMIN/R1/450/MAR,APR/Rp.89222/Adm6000/977-1071/047421CA414149E5CEC5. Saldo: 7`;
let match = regex.exec(str);
console.log(match[1]);

Best way to get the word right before a certain word in javascript

I have the following string
this is the string and THIS is the word I want
I've tried using a regex for this:
var to_search = "is"
var regex = "/\S+(?="+to_search+")/g";
var matches = string.match(regex);
And I wanted matches to contain "THIS" (word that comes after the second if) but it does not seem to be working
Any idea? Thanks

regex101.com is a really great site to test your regex and it even generates the code for you.
const regex = /\bis.*(this)/gi;
const str = `this is the string and THIS is the word I want`;
let m;
while ((m = regex.exec(str)) !== null) {
// This is necessary to avoid infinite loops with zero-width matches
if (m.index === regex.lastIndex) {
regex.lastIndex++;
}
// The result can be accessed through the `m`-variable.
m.forEach((match, groupIndex) => {
console.log(`Found match, group ${groupIndex}: ${match}`);
});
}

First you have to double backslashes when using the string form of regexes.
Second, you forgot whitespace in your pattern:
var regex = new RegExp("\\S+\\s+(?="+to_search+")", "g");