Replace last character of string using JavaScript

Question

I have a very small query. I tried using concat, charAt, slice and whatnot but I didn't get how to do it.

Here is my string:

var str1 = "Notion,Data,Identity,"

I want to replace the last , with a . it should look like this.

var str1 = "Notion,Data,Identity."

Can someone let me know how to achieve this?

score 174 · Accepted Answer · answered Apr 14 '16 at 17:39

174

You can do it with regex easily,

var str1 = "Notion,Data,Identity,".replace(/.$/,".")

.$ will match any character at the end of a string.

answered Apr 14 '16 at 17:39

Rajaprabhu Aravindasamy

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@Patrick That is regex components. `.` will match any character. And `$` will join with that dot to match any character at the end of the string. – Rajaprabhu Aravindasamy Apr 14 '16 at 19:20
@SayedMohdAli If you want to pass a dynamic regex instead of static use `new RegExp('yourRegexString')`. – Rajaprabhu Aravindasamy Aug 06 '19 at 09:37
@RajaprabhuAravindasamy does it replace? – Sayed Mohd Ali Aug 06 '19 at 09:49
I did expression = expression.replace("/"+expression[i]+"$/",""); – Sayed Mohd Ali Aug 06 '19 at 09:49
@SayedMohdAli Use it like, `result = yourString.replace(new RegExp('yourRegex'), "")` – Rajaprabhu Aravindasamy Aug 06 '19 at 09:53
did not work out expression = expression.replace(new RegExp('/'+expression[i]+'$/'), "") – Sayed Mohd Ali Aug 06 '19 at 09:56
is there any shortest way example I want to remove last A from the string AABBAA? but that last A is dynamic and can be last B .... – Sayed Mohd Ali Aug 06 '19 at 09:58
@SayedMohdAli `expression = expression.replace(new RegExp(expression[i]+'$'), "")` You don't need to include the slashes. – Rajaprabhu Aravindasamy Aug 06 '19 at 11:23

score 92 · Answer 2 · answered Apr 14 '16 at 17:41

You can remove the last N characters of a string by using .slice(0, -N), and concatenate the new ending with +.

var str1 = "Notion,Data,Identity,";
var str2 = str1.slice(0, -1) + '.';
console.log(str2);

Notion,Data,Identity.

Negative arguments to slice represents offsets from the end of the string, instead of the beginning, so in this case we're asking for the slice of the string from the beginning to one-character-from-the-end.

score 12 · Answer 3 · edited Dec 10 '16 at 22:53

12

This isn't elegant but it's reusable.

term(str, char)

str: string needing proper termination

char: character to terminate string with

var str1 = "Notion,Data,Identity,";

function term(str, char) {
  var xStr = str.substring(0, str.length - 1);
  return xStr + char;
}

console.log(term(str1,'.'))

edited Dec 10 '16 at 22:53

Jed Fox

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answered Apr 14 '16 at 17:54

zer00ne

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score 6 · Answer 4 · answered Jul 31 '21 at 03:11

6

You can use simple regular expression

var str1 = "Notion,Data,Identity,"
str1.replace(/,$/,".")

answered Jul 31 '21 at 03:11

MD SHAYON

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Replace last character of string using JavaScript

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