In your page components, you can execute code only in the server-side or on the client-side, but checking the window property.
This property is only existing inside the browser, so you can check
if (typeof window === 'undefined') {
}
and add the server-side code in that block.
Similarly, you can execute client-side code only by checking
if (typeof window !== 'undefined') {
}
JS Tip: We use the
typeofoperator here because we can’t detect a value to be undefined in other ways. We can’t doif (window === undefined)because we’d get a “window is not defined” runtime error
Next.js, as a build-time optimization, also removes the code that uses those checks from bundles. A client-side bundle will not include the content wrapped into a if (typeof window === 'undefined') {} block.
One more thing! ⚠️ ✋
At the end of January I will organize the Web
Development
Bootcamp.
It's a 10-weeks long cohort online course where I will guide you to becoming a Web Developer.
It's not "just a course". It's a big event I organize once a year.
We'll start from zero, learn the fundamentals of Web Development, HTML CSS, JavaScript, Tailwind, Git, using the command line, VS Code, GitHub, Node.js, we'll then learn React, JSX, how to use PostgreSQL, Astro, Next.js, Prisma, deploying on Netlify/DigitalOcean/Fly/Vercel and much more!
At the end of the first 10 weeks you'll know how to create web sites and web applications and I'll unlock you the 2nd phase of the Bootcamp: you will get access to a large number of projects exclusive to the Bootcamp graduates, so you can follow my instructions to build things like private areas with authentication, clones of popular sites like Twitter YouTube Reddit, create e-commerce sites, and much much more.
Because once you got the fundamentals, you only learn by working on real, exciting projects.
To find out more, visit bootcamp.dev
It's a 10-weeks long cohort online course where I will guide you to becoming a Web Developer.
It's not "just a course". It's a big event I organize once a year.
We'll start from zero, learn the fundamentals of Web Development, HTML CSS, JavaScript, Tailwind, Git, using the command line, VS Code, GitHub, Node.js, we'll then learn React, JSX, how to use PostgreSQL, Astro, Next.js, Prisma, deploying on Netlify/DigitalOcean/Fly/Vercel and much more!
At the end of the first 10 weeks you'll know how to create web sites and web applications and I'll unlock you the 2nd phase of the Bootcamp: you will get access to a large number of projects exclusive to the Bootcamp graduates, so you can follow my instructions to build things like private areas with authentication, clones of popular sites like Twitter YouTube Reddit, create e-commerce sites, and much much more.
Because once you got the fundamentals, you only learn by working on real, exciting projects.
To find out more, visit bootcamp.dev