CODEWITHSUNDEEP
javascriptregex
vaibhav
vaibhav

Reputation: 784

regular expression to get 4th character from last

I have been trying to get a regular expression that can pick the last fourth character in the string.

For Ex. If "system" is a string I want to pick "s", I cannot check that from starting as the number of characters from start are not fixed.

So far I have only reached to : /.{3}$/g , but it is taking last three character ans not the character after that.

Can someone help me in the same?

Upvotes: 0

Views: 2330

Answers (5)

Rawling
Rawling

Reputation: 50164

.(?=.{3}$) works with the whole expression matching, not just a capturing group.

Upvotes: 3

Hemant Pathak
Hemant Pathak

Reputation: 68

try using /([a-z]).{3}$/g then in your result, you can use the value from first capture group. Change the class just in case you want a wider or different selection

Upvotes: 0

Developer
Developer

Reputation: 428

why not using substring like that :

function lastFourLetters(str)
{
   if (str.length < 5)
       return str;
   return str.substring(str.length - 4 , 4); 
}

Upvotes: 0

Phortuin
Phortuin

Reputation: 770

You’d have to use a group:

/(.).{3}$/

The full match here will be stem, and group 1 would be s (you can see for yourself here: https://regex101.com/r/dZwhcu/1)

You could solve it as follows:

var matches = 'system'.match(/(.).{3}$/); //=> ['stem', 's']
if (matches[1] === 's') {
    // ...
}

Upvotes: 2

synthet1c
synthet1c

Reputation: 6282

const reg = /.*(.).{3}$/g
const str = 'this is astring'

console.log(
  str.replace(reg, '$1')
)

Upvotes: 0

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