How to use javascript to implement four arithmetic operations

In Web development, JavaScript is a very popular programming language. Using JavaScript can achieve many interesting functions, such as using JavaScript to implement simple four arithmetic operations. Through this article, we will introduce how to use JavaScript to implement four arithmetic operations.

1. HTML structure

First, we need to create an HTML file and add a text box for entering expressions, buttons for four operators and a button for The area where results are displayed. The HTML code is as follows:

nbsp;html>


    <meta>
    <title>用JavaScript实现四则运算</title>


    <input>
    <button>+</button>
    <button>-</button>
    <button>*</button>
    <button>/</button>
    <p></p>
    <script></script>

In this HTML structure, we use the input element as the text box for input expressions, the button element as the button for the four operators, and add the calculate function to these buttons transfer. In addition, we also added an area for displaying results. The id attribute of the p element is result. We will use this id to obtain the area for displaying results.

2. JavaScript code

Next, we need to write a JavaScript file to implement the four arithmetic operations. The JavaScript code is as follows:

function calculate(operator) {
    var expression = document.getElementById("expression").value; //获取表达式
    var operArr = expression.split(operator); //分割表达式
    var numArr = []; //存储数字
    for(var i = 0; i <p>In this JavaScript code, we define a calculate function to perform four arithmetic operations on the input expression. In the function, we first obtain the expression entered by the user through document.getElementById("expression").value, then split the expression into two numbers through the split method, and store the two numbers in an array. Then, the four operators are processed differently through the switch statement, and finally the results are displayed on the page through document.getElementById("result").innerHTML. </p><p>3. After writing the code using </p><p>, we only need to open the HTML file in the browser, enter an expression, select an operator, and then click the equal sign to get the operation The results are displayed on the page. As shown below: </p><p><img src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/article/000/000/068/168075020156607.png" class="lazy" alt="How to use javascript to implement four arithmetic operations" title="How to use javascript to implement four arithmetic operations"></p><p>4. Summary</p><p>Through the introduction of this article, we can see that it is very simple to implement simple four arithmetic operations in JavaScript. . With only some basic JavaScript syntax and HTML structure, we can easily implement the four arithmetic operations. I hope this article can be helpful to everyone when learning and using JavaScript. </p>

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