What is the method of generating random numbers in js

The js method to generate random numbers is to use the Math.random() method, Date object method and custom function. Detailed introduction: 1. Math.random() method, you can generate the required random numbers by multiplying the size of a range; 2. Date object method, you can use the Date object method to generate random numbers; 3. Custom function , you can use an array to store some predefined numbers, and then use the Math.random() method to randomly select a number.

JS (JavaScript) is a scripting language widely used in web development. It provides many built-in functions and methods, including methods for generating random numbers. . In JS, there are many ways to generate random numbers, and several of the commonly used methods will be introduced below.

1. Math.random() method:

The Math.random() method returns a random floating point number between 0 and 1. The desired random number can be generated by multiplying the size of a range. For example, to generate a random integer between 1 and 10, you can use the following code:

var randomNumber = Math.floor(Math.random() * 10) + 1;

The Math.floor() function here is used to round down to ensure that the generated random number is an integer.

2. Date object methods:

The Date object is a built-in object in JS for processing dates and times. You can use the Date object's methods to generate random numbers. For example, you can use the getTime() method to get the number of milliseconds of the current time and use it as a seed for a random number. Some algorithm can then be used to generate random numbers in the desired range. The following is a sample code:

var currentDate = new Date();
var seed = currentDate.getTime();
var randomNumber = (seed * 9301 + 49297) % 233280;
randomNumber = randomNumber / 233280;
randomNumber = Math.floor(randomNumber * 10) + 1;

The algorithm here is a simple linear congruential algorithm that can generate a random integer between 1 and 10.

3. Custom functions:

In addition to using the built-in methods, you can also customize functions to generate random numbers. For example, you can use an array to store some predefined numbers, and then use the Math.random() method to randomly select a number. The following is a sample code:

function getRandomNumber() {
var numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
var randomIndex = Math.floor(Math.random() * numbers.length);
return numbers[randomIndex];
}
var randomNumber = getRandomNumber();

The getRandomNumber() function here will return a random integer between 1 and 10.

Summary:

The above introduces several common methods to generate random numbers. Depending on the specific needs and scenarios, you can choose a suitable method to generate random numbers within the required range. Whether using Math.random() method, Date object method or custom function, you can easily generate random numbers in JS .

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