What is the difference between static positioning and dynamic positioning

What is the difference between static positioning and dynamic positioning

In web development, positioning refers to placing elements at specific locations on the page. Static positioning and dynamic positioning are two commonly used methods, and they have some obvious differences.

1. Definition
   Static positioning is the most basic positioning method, which is achieved by setting the position attribute of CSS to static. Under static positioning, elements are placed in the order they appear in the HTML document and will not be affected by the position of other elements. This method is suitable for elements that do not require special positioning requirements.
   Dynamic positioning is achieved by setting the position attribute of CSS to relative, absolute or fixed. Under dynamic positioning, the position of an element can be positioned relative to its nearest parent element or root element with a positioning attribute by adjusting the top, bottom, left, and right attributes.
2. Layout Impact
   Static positioning does not have any impact on layout, and elements are naturally arranged in the order they appear in the HTML document. Dynamic positioning will cause the element to break away from the normal document flow, and other elements will ignore the position of the positioned element, which may cause layout changes.
3. Element overlap
   Under static positioning, elements will not overlap, they will be placed sequentially in the order of the document flow. Under dynamic positioning, elements can precisely control their position by setting the top, bottom, left, and right attributes, which may cause overlap between elements.

The following is a specific code example to illustrate the difference between static positioning and dynamic positioning:

HTML code:

<div class="container">
   <div class="static-position">我是静态定位元素</div>
   <div class="relative-position">我是相对定位元素</div>
   <div class="absolute-position">我是绝对定位元素</div>
   <div class="fixed-position">我是固定定位元素</div>
</div>

CSS code:

.container {
   position: relative;
   height: 200px;
   width: 200px;
   border: 1px solid black;
}

.static-position {
   position: static;
   background-color: red;
}

.relative-position {
   position: relative;
   top: 20px;
   left: 20px;
   background-color: green;
}

.absolute-position {
   position: absolute;
   top: 50px;
   right: 20px;
   background-color: blue;
}

.fixed-position {
   position: fixed;
   bottom: 20px;
   left: 20px;
   background-color: yellow;
}

In the above example, the container div is set to relative positioning, and the position of the statically positioned element is not adjusted; the relatively positioned element is offset 20px downward and to the right relative to its position in the normal document flow; the absolutely positioned element is relatively It is positioned relative to the top 50px and the right 20px of the container div; the fixed positioning element is positioned relative to the bottom 20px and the left 20px of the browser window.

Through the above examples, we can clearly see the difference between static positioning and dynamic positioning in terms of the position and layout of elements. Static positioning allows elements to be naturally arranged according to the flow of the document, while dynamic positioning allows you to control the position of elements by adjusting the top, bottom, left, and right attributes to achieve a more flexible layout effect.

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