In front-end development, what is the viewport on a mobile device? How to set the viewport of the page through the meta attribute in the header tag.

The viewport on a mobile device refers to the area of ​​a web page that is visible on a mobile device. Due to the different screen sizes and resolutions of mobile devices, in order to ensure that web pages can be displayed and interacted correctly on various devices, it is necessary to adapt to different screen sizes through viewport settings.

On mobile devices, web pages are usually wider than on desktop computers, so they need to be scaled and adapted to fit the smaller screen. The viewport setting is implemented through the attribute <meta>in the tag , and the specific settings can control the following aspects:viewport

1. width: Sets the width of the viewport. Usually it can be set to the width of the device so that the web page fills the entire screen.

2. initial-scale: Set the initial zoom level, used to control the initial size of the page.

3. minimum-scaleand maximum-scale: Set the zoom minimum and maximum range to limit the user's zoom operation.

4. user-scalable: Controls whether the user can manually zoom the page.

Here is an example viewport setting:

<meta name="viewport" content="width=device-width, initial-scale=1.0">

In this example, width=device-widthit means that the width of the viewport will be equal to the width of the device, initial-scale=1.0and the initial zoom level is 1.0, that is, no zoom. This makes the page appear at its original size on mobile devices, with a width equal to the device's screen width.

With proper viewport settings, you can ensure that your web pages display well on a variety of mobile devices without clipped or oversized content. At the same time, the viewport setting also affects the user's interactive experience, so that the user can browse and use the webpage more conveniently.

Q: If the webpage is only displayed on the PC side, is it necessary to set the viewport property of the meta?
Yes, if your webpage is only displayed on the PC side, you usually don't need to set the attribute <meta>of the tag viewport. viewportAttributes are primarily used in responsive design on mobile devices to ensure that web pages display and interact correctly on different screen sizes.

On the PC side, browsers usually use default viewport settings to fit the size of the desktop screen. Therefore, for web pages that are only displayed on the PC side, viewportit is usually appropriate not to set the attribute.

If your webpage is displayed for both PC and mobile devices, you can consider setting appropriate viewportproperties according to the situation to ensure that the display effect on mobile devices is also good. However, if it is only displayed on the PC side, it is not necessary to set viewportthe attribute.