How to make two pictures overlap in javascript

JavaScript is a commonly used web programming language that can be used to achieve dynamic effects and interactive functions on web pages. In web design, it is often necessary to add graphic elements to the web page to beautify the page, and if two graphics are overlapped, some special effects can also be produced. So, how to make two graphics overlap in JavaScript? Let’s discuss this issue together.

1. Overlap two graphics through CSS

In CSS, there is a property called "position", which is used to specify the positioning method of an element in the document, including static, relative, Absolute, fixed and other methods. If you want to overlap two graphics, you can do so by modifying the "position" attribute of the element. The specific operations are as follows:

1. Add two graphic elements to the HTML page.

<div>图形1</div>
<div>图形2</div>

2. Set the styles of two graphic elements in CSS, including width, height, color and other attributes.

#box1 {
    width: 200px;
    height: 200px;
    background-color: red;
}

#box2 {
    width: 100px;
    height: 100px;
    background-color: blue;
}

3. Position the element to the specified position by modifying the "position" attribute.

#box1 {
    width: 200px;
    height: 200px;
    background-color: red;
    position: relative;
    z-index: 1;
}

#box2 {
    width: 100px;
    height: 100px;
    background-color: blue;
    position: absolute;
    top: 50px;
    left: 50px;
    z-index: 2;
}

In the above code, we set the "position" attribute of the "box1" element to "relative", which means that the position of the element is positioned relative to its original position; set the "box2" element's The "position" attribute is set to "absolute", which means that the element is positioned relative to its parent element. Then, we set the "top" and "left" properties of the "box2" element to position it exactly in the center of the "box1" element. Since the "z-index" attribute value of the "box2" element on the "z" axis is 2, and the "z-index" attribute value of the "box1" element is 1, the "box2" element will be displayed on "box1" above the element, thus achieving the overlapping effect of the two elements.

2. Overlapping two graphics through JavaScript

In addition to overlapping two graphics through CSS, we can also implement it through JavaScript. The specific approach is to dynamically create two elements through JavaScript and add them to the page. Then, overlay the two elements by modifying their styles. The specific operations are as follows:

1. Add a container element to the HTML page as the parent element of the dynamically added element.

<div></div>

2. Use JavaScript to dynamically create two elements and set their style and content.

// 创建元素
var box1 = document.createElement('div');
var box2 = document.createElement('div');

// 设置内容和样式
box1.innerHTML = '图形1';
box1.style.width = '200px';
box1.style.height = '200px';
box1.style.backgroundColor = 'red';

box2.innerHTML = '图形2';
box2.style.width = '100px';
box2.style.height = '100px';
box2.style.backgroundColor = 'blue';

3. Add the two created elements to the container element.

// 获取容器元素
var container = document.getElementById('container');

// 将元素添加到容器元素中
container.appendChild(box1);
container.appendChild(box2);

4. Overlap the two elements by modifying their styles.

// 设置位置和层级关系
box1.style.position = 'relative';
box2.style.position = 'absolute';
box2.style.top = '50px';
box2.style.left = '50px';
box2.style.zIndex = '2';

In the above code, we first dynamically create two elements "box1" and "box2" through JavaScript, and then add them to a container element in the page. Next, we overlap them by modifying their styles. Similarly, we set the "position" attribute of the "box1" element to "relative", which means that the element is positioned relative to its original position; we set the "position" attribute of the "box2" element to "absolute", which means that the element is positioned relative to its original position. Position relative to its parent element; position it to the exact center of the "box1" element via the "top" and "left" attributes, and set its "z-index" attribute value on the "z" axis to 2 , to appear above the "box1" element.

3. Summary

Through CSS and JavaScript, we can achieve the overlapping effect of two graphics on the web page, adding some special visual effects and artistic sense to the web page. Using both methods requires modifying the style of the element. The method implemented through JavaScript can be more flexible and can construct dynamic effects and interactions. Understanding the impact of CSS and JavaScript on the positioning and hierarchical relationship of elements can better realize creativity and effects in web design.

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