Sentry Answers>JavaScript>

How do I remove/chop/slice/trim off the last character in a string using Javascript?

How do I remove/chop/slice/trim off the last character in a string using Javascript?

David Y.

—

The Problem

How can I remove the last character from a string in JavaScript?

The Solution

Strings in JavaScript are immutable, so whenever we want to manipulate one, we must create a new string with our desired changes. Therefore, to remove the last character of a string, we must create a new string that excludes it. Two commonly used methods for this are slice and substring.

Using slice

slice allows us to extract a substring by specifying inclusive start and end indices within the original string. Negative numbers are used to count backwards from the end of the string rather than forwards from the start, so -1 will refer to the second-last character. Consider the following example:

Click to Copy
let myString = "Hello world!";

myString = myString.slice(0, -1);

console.log(myString); // will print "Hello world"

Using substring

The substring method is similar to slice but does not allow us to specify negative indices. Therefore, we must provide the positive index of the end position by subtracting 1 from the length of the string. Note also that the substring returned will stop just before the character at the index specified in the second argument, unlike slice, which includes the final character.

Click to Copy
let myString = "Hello world!";

myString = myString.substring(0, myString.length - 1);

console.log(myString); // will print "Hello world"

Comparison

The slice method is terser and its syntax will be familiar to Python programmers, but it may be initially confusing to programmers who have not previously encountered it. The substring method is more verbose but also more explicit.

  • ResourcesImprove Web Browser Performance - Find the JavaScript code causing slowdowns
  • SentryJavascript Error Monitoring & Tracing
  • ResourcesJavaScript Frontend Error Monitoring 101
  • Syntax.fmListen to the Syntax Podcast
  • Syntax.fm logo
    Listen to the Syntax Podcast

    Tasty treats for web developers brought to you by Sentry. Get tips and tricks from Wes Bos and Scott Tolinski.

    SEE EPISODES

Considered “not bad” by 4 million developers and more than 100,000 organizations worldwide, Sentry provides code-level observability to many of the world’s best-known companies like Disney, Peloton, Cloudflare, Eventbrite, Slack, Supercell, and Rockstar Games. Each month we process billions of exceptions from the most popular products on the internet.

learn more about sentryjoin our discord
© 2024 • Sentry is a registered Trademark of Functional Software, Inc.