CODEWITHSUNDEEP
javascriptregex
Balkrishna Pathak
Balkrishna Pathak

Reputation: 47

How to extract string in regex

I have string in this format:

var a="input_[2][invoiceNO]";

I want to extract "invoiceNo" string. I've tried:

var a="input_[2][invoiceNO]";
    var patt = new RegExp('\[(.*?)\]');
    var res = patt.exec(a);

However, I get the following output:

Array [ "[2]", "2" ]

I want to extract only invoiceNo from the string.

Note: Input start can be any string and in place of number 2 it can be any number.

Upvotes: 1

Views: 60

Answers (6)

Wiktor Stribiżew
Wiktor Stribiżew

Reputation: 626689

I would check if the [...] before the necessary [InvoiceNo] contains digits and is preceded with _ with this regex:

/_\[\d+\]\s*\[([^\]]+)\]/g

Explanation:

  • _ - Match underscore
  • \[\d+\] - Match [1234]-like substring
  • \s* - Optional spaces
  • \[([^\]]+)\] - The [some_invoice_123]-like substring

You can even use this regex to find invoice numbers inside larger texts.

The value is in capture group 1 (see m[1] below).

Sample code:

var re = /_\[\d+\]\s*\[([^\]]+)\]/g; 
var str = 'input_[2][invoiceNO]';
while ((m = re.exec(str)) !== null) {
    alert(m[1]);
}

Upvotes: 2

Avinash Raj
Avinash Raj

Reputation: 174696

Use the greediness of .*

var a="input_[2][invoiceNO]";
var patt = new RegExp('.*\[(.*?)\]');
var res = patt.exec(a);

Upvotes: 0

npinti
npinti

Reputation: 52185

You could use something like so: \[([^[]+)\]$. This will extract the content within the last set of brackets. Example available here.

Upvotes: 0

n-dru
n-dru

Reputation: 9420

Try this:

var a="input_[2][invoiceNO]";
var patt = new RegExp(/\]\[(.*)\]/);
var res = patt.exec(a)[1];
console.log(res);

Output:

invoiceNO

Upvotes: 0

vks
vks

Reputation: 67968

var a="input_[2][invoiceNO]";
var patt = new RegExp('\[(.*?)\]$');
var res = patt.exec(a);

Upvotes: 0

anubhava
anubhava

Reputation: 784898

You can use this regex:

/\[(\w{2,})\]/

and grab captured group #1 from resulting array of String.match function.

var str = 'input_[2][invoiceNO]'
var m = str.match(/\[(\w{2,})\]/);
//=> ["[invoiceNO]", "invoiceNO"]

PS: You can also use negative lookahead to grab same string:

var m = str.match(/\[(\w+)\](?!\[)/);

Upvotes: 0

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