How to use JavaScript to generate random numbers and change them regularly

With the increasing development of Internet technology, JavaScript has become one of the most popular programming languages ​​in recent years. Not only can it be used to develop websites and mobile applications, but it can also implement various interesting functions such as random number generation. This article will show you how to use JavaScript to generate random numbers and change them after a few seconds.

JavaScript generates random numbers

In JavaScript, the Math.random() function can be used to generate a random number, which will return a floating point number between 0 and 1. For example, the following code will generate a random number and print it to the console:

var randomNum = Math.random();
console.log(randomNum);

If you want to generate a random number within a specified range, you can use the following code:

var min = 1;
var max = 100;
var randomNum = Math.floor(Math.random() * (max - min + 1)) + min;
console.log(randomNum);

The above code will generate an integer between 1 and 100.

Set the timer

To make the random number change after a few seconds, we need to use the timer function in JavaScript. The characteristic of a timer is that it can delay the execution of code or repeatedly execute a specific block of code. In this example, we will use the setTimeout() function, which will be executed once after a specified time.

Below is a sample code that will generate a random number and output it to the console. Then it will delay for 5 seconds and generate a new random number again and output it to the console.

var randomNum = Math.random(); // 生成随机数
console.log(randomNum); // 输出随机数

setTimeout(function() {
   var newRandomNum = Math.random(); // 生成新的随机数
   console.log(newRandomNum); // 输出新的随机数
}, 5000); // 延时5秒钟

As shown above, we use the setTimeout() function to set a delayer, which will execute the anonymous function after 5 seconds. The anonymous function will generate a new random number and print it to the console.

Applying random numbers to actual situations

By generating random numbers and setting timers, we can apply them to actual situations, such as changing page content through random numbers. Below is a code snippet that will display a random background color on the page and then change it to another random color after 3 seconds.

function changeBackgroundColor() {
   var red = Math.floor(Math.random() * 256);
   var green = Math.floor(Math.random() * 256);
   var blue = Math.floor(Math.random() * 256);
   var bgColor = "rgb(" + red + "," + green + "," + blue + ")";
   document.body.style.background = bgColor; // 更改背景颜色

   setTimeout(function() {
      var newRed = Math.floor(Math.random() * 256);
      var newGreen = Math.floor(Math.random() * 256);
      var newBlue = Math.floor(Math.random() * 256);
      var newBgColor = "rgb(" + newRed + "," + newGreen + "," + newBlue + ")";
      document.body.style.background = newBgColor; // 更改背景颜色
   }, 3000); // 延时3秒钟
}

changeBackgroundColor();

As mentioned above, the changeBackgroundColor() function will generate a random background color and apply it to the HTML page. It will then set a delayer that will execute the anonymous function after 3 seconds and generate a new random color and apply it to the page.

Summary

In this article, we introduced how to use JavaScript to generate random numbers and apply them to real-world situations. We also explored how to use timer functionality to delay the execution of code, specifically using the setTimeout() function. In addition to applying random numbers in this example, random numbers in JavaScript can also be applied to other scenarios, such as games, password generation, and data analysis.

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