html set the size of the picture

In the process of web design, pictures are an element that is often used. However, if the image size is inappropriate, it will affect the layout and aesthetics of the entire page. Therefore, for different needs, we need to set the size of the image to adapt to the design of the page. This article will introduce you to how to set the image size in HTML.

1. Use the width and height attributes

In HTML, we can use the width and height attributes to set the size of the image. The value of these two attributes can be a specific pixel value or a relative value. Relative values ​​include percentage and em, where percentage refers to the size relative to the parent element, and em refers to the size relative to the current element.

When we use the width and height attributes to set the size of the image, it can be implemented in the following way:

<img src="image.jpg" width="200" height="100">

In the above code, the width and height attributes are set to 200 and 100 respectively. This means that the width of the image will be 200 pixels and the height will be 100 pixels. However, if you set the width and height to different pixel values, the image may become distorted, so it's better to use the same proportions.

If you want to set the size of the image to a relative value, you can do it in the following way:

<img src="image.jpg" width="50%" height="50%">

In the above code, the width and height attributes are set to 50% respectively. This means that the width and height of the image will be equal to 50% of its parent element.

2. Use CSS styles to set the size of images

In HTML, we can also use CSS styles to set the size of images. This approach is more flexible and can adapt to different needs. CSS styles can be applied to the entire page or to an element of a partial page.

If you want to set the size of the image in CSS, you can use the following code:

img{
  width: 200px;
  height: 100px;
}

In the above code, we use the CSS img selector to select the image and set the width and height are both set to 200px and 100px.

If you want to set the size of the image to a relative value, you can use the following code:

img{
  width: 50%;
  height: 50%;
}

In the above code, we still use the CSS img selector, but change the width and height Both are set to 50%.

3. Use the class or id attribute in HTML to set the size of the image

If you only want to set the size of a certain image, you can use the class or id attribute in HTML to achieve this. . In order to use the class or id attribute, you need to first define the corresponding style in CSS and use the class or id selector to select the element.

The following code demonstrates how to use the id attribute to set the size of an image:

#myImg{
  width: 200px;
  height: 100px;
}

<img id="myImg" src="image.jpg">

In the above code, we select the image element by defining an id selector in CSS, and The id attribute "myImg" is used to match the element. We then set the width and height of this element to both 200 pixels and 100 pixels.

If you want to use the class attribute to set the size of the image, you can do it in the following way:

.myImg{
  width: 50%;
  height: 50%;
}

<img class="myImg" src="image.jpg">

In the above code, we use the class attribute "myImg" and in the CSS The .myImg class selector is defined to select elements. Then, we set both the width and height of the element to 50%.

Summary

Setting the image size in HTML is a common requirement in web design. This article introduces the use of width and height attributes, CSS styles, class attributes and id attributes to set the size of images in HTML. Based on actual needs, you can choose the method that suits you. However, please note that if you use fixed pixel size images, you may impact responsive design and accessibility. Therefore, please use caution when using images.

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