Equivalent of printf or String.Format in JavaScript

David Y.

The Problem

In JavaScript, how can I print strings containing the values of variables? I would use printf() to do this in C or PHP and string.Format() to do this in C# or String.format() in Java. What is the JavaScript equivalent of these functions?

The Solution

Modern JavaScript supports template strings delimited with backticks, which can contain arbitrary JavaScript expressions inside one or more ${} blocks. For example:

const myNum = 20; const myString = `The value of myNum is ${myNum}`; const myString2 = `The value of myNum + 10 is ${myNum + 10}`; console.log(myString); // will print "The value of myNum is 20" console.log(myString2); // will print "The value of myNum + 10 is 30"

Get Started With Sentry

Get actionable, code-level insights to resolve JavaScript performance bottlenecks and errors.

  1. Create a free Sentry account

  2. Create a JavaScript project and note your DSN

  3. Grab the Sentry JavaScript SDK

<script src="https://browser.sentry-cdn.com/7.104.0/bundle.min.js"></script>
  1. Configure your DSN
Sentry.init({ dsn: 'https://<key>@sentry.io/<project>' });

Check our documentation for the latest instructions.

Loved by over 4 million developers and more than 90,000 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.

Share on Twitter
Bookmark this page
Ask a questionJoin the discussion

Related Answers

A better experience for your users. An easier life for your developers.

    TwitterGitHubDribbbleLinkedinDiscord
© 2024 • Sentry is a registered Trademark
of Functional Software, Inc.