javascript presses different buttons and the text box displays words of different colors

With the development of Internet technology, JavaScript has become an indispensable programming language in website development. The advantage of JavaScript is that it can run in the browser, and it can also be used with HTML and CSS to achieve dynamic web page effects. This article will introduce how to use JavaScript to display words of different colors in the text box when different buttons are pressed.

Implementation Ideas

Before achieving this goal, we need to understand some basic knowledge of JavaScript. JavaScript mainly uses DOM (Document Object Model) to achieve dynamic effects on web pages. The DOM parses web pages into a series of nodes and objects that can be manipulated through JavaScript. The following is the JavaScript knowledge needed for this implementation:

1. Get page elements: Use JavaScript to get elements in the page by ID or class name. For example, we can get the ID of an element through the document.getElementById() method, or get the class names of a group of elements through the document.getElementsByClassName() method.
2. Listening to events: JavaScript can add event listeners to perform corresponding actions when web page events occur. For example, we can use the .addEventListener() method to listen for mouse clicks, keyboard presses, mouse movements and other events.
3. Modify element attributes: JavaScript can achieve dynamic effects on web pages by modifying element attributes. For example, we can modify the color of the element's font through the .style.color attribute, and modify the text content of the element through the .innerHTML attribute.

Now that we have the above basic knowledge, we can start to implement the function of displaying words of different colors in the text box when different buttons are pressed. The specific steps are as follows:

1. Create a text box and three buttons (red button, yellow button, green button).
2. Use JavaScript to get the elements of the text box and three buttons.
3. Add three button click event listeners. When the user clicks a button, the corresponding function is triggered.
4. In the corresponding function, modify the style of the text box to display words of the corresponding color.
5. Finally, test whether the function is normal.

Implementation code

The following is the JavaScript code to display words of different colors in the text box when different buttons are pressed:

// 获取文本框和三个按钮的元素
var text_box = document.getElementById("text-box");
var red_button = document.getElementById("red-button");
var yellow_button = document.getElementById("yellow-button");
var green_button = document.getElementById("green-button");

// 添加三个按钮的点击事件监听器
red_button.addEventListener("click", function() {
    // 将文本框的样式修改为红色
    text_box.style.color = "red";
});

yellow_button.addEventListener("click", function() {
    // 将文本框的样式修改为黄色
    text_box.style.color = "yellow";
});

green_button.addEventListener("click", function() {
    // 将文本框的样式修改为绿色
    text_box.style.color = "green";
});

It should be noted that , when implementing the code, you need to obtain the elements of the text box and three buttons correctly, otherwise the code will not work properly.

Summary

This article introduces how to use JavaScript to realize the function of displaying words of different colors in the text box when pressing different buttons. Among them, we implement this function through the basic knowledge of JavaScript (obtaining page elements, listening to events, and modifying element attributes).

We hope that through this article, we can help beginners better understand how to use JavaScript. We also hope that everyone can deepen their understanding of JavaScript through practice.

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