{"id":1524,"date":"2019-08-10T10:54:48","date_gmt":"2019-08-10T10:54:48","guid":{"rendered":"https:\/\/www.copahost.com\/blog\/?p=1524"},"modified":"2020-05-31T13:52:00","modified_gmt":"2020-05-31T13:52:00","slug":"math-random-javascript","status":"publish","type":"post","link":"https:\/\/www.copahost.com\/blog\/math-random-javascript\/","title":{"rendered":"Math Random in Javascript: generating random numbers"},"content":{"rendered":"

Javascript provides a vast amount of math-related functions. In this article, we will explain how to use Math Random in Javascript. These in-built functions and objects are very useful while programming and developing. In-built functions and objects reduce the work for the developers. Some of the most commonly used in-built javascript functions and objects are parseFloat, parseInt, math, String<\/a>, Number, etc. In-built objects in javascript have different methods and properties which extend their working in different variations. In this article, we will learn about one such object known as math, and its method, random.<\/p>\n

The math random method<\/h3>\n

Math object provides various properties and methods. Random is one of the methods of math objects in javascript. We can use the random function to get a random number between 0 (inclusive) and 1 (exclusive). The result we get is a floating-point<\/a> number which can include 0, but not 1. The random function is a useful function while developing such apps that require a random number to a decision.<\/p>\n

The following examples show a random function used to generate a random floating-point number.<\/p>\n

var result1 = Math.random();\r\nvar result2 = Math.random();\r\nvar reuslt3 = Math.random();\r\n\r\n\/\/result1 = 0.38628229857168694\r\n\/\/result2 = 0.4474997248824282\r\n\/\/result3 = 0.14050962942617873<\/pre>\n
The output is:<\/p>\n
\"\"<\/p>\n
The result is different every time. We always get a different floating-point number than the previous one. The random function can be used to make random decisions also. Let’s discuss random decision making using a random function.<\/p>\n
var number = Math.random();\r\nvar result;\r\nif(number <= 0.5)\r\n{\r\n  result = 1;\r\n}\r\nelse{\r\n   result = 0;\r\n}\r\n<\/pre>\n
Observe the above code. We used a variable named as the number and gave it any random number using Math.random function. In the if condition, we compared the number variable with 0.5. If it is less than or equal to 0.5, then the result is equal to 1 or else, it equals 0. This is random decision making.<\/p>\n
Random function with a range<\/h3>\n
The random function of the math object by default returns a floating-point number between the range 0 (inclusive) and 1 (exclusive), but with certain different modifications using other functions, we can also extend the range. This can be done in two ways. Let’s discuss these ways of using the random function with range.<\/p>\n
The range between 0 and a maximum value<\/h4>\n
This is one easy way of using math’s random function. We can get a random number between 0 and a specified maximum value by little modification.<\/p>\n
var result1 =  Math.random() * 10;\r\nvar result2 =  Math.random() * 10;\r\nvar reuslt3 =  Math.random() * 10;\r\n\r\n\/\/result1 = 1.9409498473136177\r\n\/\/result2 = 3.6785094083002634\r\n\/\/result3 = 0.04600099618988773<\/pre>\n
The output is:<\/p>\n
\"Math<\/p>\n
In the above example, we simply multiplied the returned value of the random function with 10. This will create a random number within the range, 0 and 10. We can use any number in the place of 10 and multiplying it with the random function will give a random number between 0 and that specified number.<\/p>\n
The range between a minimum and maximum value<\/h4>\n
We can also get a random number between two specified numbers. There is a special logic for this. The following example shows how to get a random number between a minimum and maximum value.<\/p>\n
var min = 50;\r\nvar max = 100;\r\n\r\nvar result1 = Math.random()*(max - min)+min;\r\nvar result2 = Math.random()*(max - min)+min;\r\nvar result3 = Math.random()*(max - min)+min;\r\n\r\n\/\/result1 = 64.41960433466932\r\n\/\/result2 = 91.59727835073954\r\n\/\/result3 = 76.15457234855353<\/pre>\n
The output is:<\/p>\n
\"\"<\/p>\n
In the above example, we declared two variables, min, and max, with values 50 and 100 respectively. To get a random number between these two values, first, we have to take the difference of both values and add it to the minimum value. The sum is then multiplied with the return value of the random function. The random number generated is always between the range we specified.<\/p>\n
Javascript Math Randon with Integer numbers<\/h3>\n
We can see that the returned random number is always a floating-point<\/a> number. What if we want an integer or whole number? We can use math object’s two other functions for this, ceil and floor. Let understand these two functions and their use with the help of an example.<\/p>\n
var min = 50; \r\nvar max = 100; \r\n\r\nvar result1 = Math.ceil(Math.random()*(max - min)+min); \r\nvar result2 = Math.floor(Math.random()*(max - min)+min);\r\n\r\n\/\/result1 = 95\r\n\/\/result2 = 62<\/pre>\n
The output is:<\/p>\n
\"object\"<\/p>\n
In the above example, we used the random function to generate random numbers. But the output is not a floating-point number. This is because we passed the random function to the math’s ceil and floor function. The value returned from both the function is an integer. The ceil function round-offs the floating-point number upwards to the nearest integer while the floor function round-offs it downwards to the nearest integer.<\/p>\n
Math random function into an array<\/h3>\n
We can also generate an array of random numbers using the random function in javascript<\/a>. We need to generate random numbers in a for loop to create the array<\/a>. The following code shows how to create<\/a> an array of random numbers using the math random Javascript function.<\/p>\n
var result;\r\nvar arr = [];\r\nfor(var i=0;i<5;i++)\r\n{\r\n    result  = Math.random();\r\n    arr.push(result)\r\n}\r\n\r\n\/\/ arr = [0.7493301502756253,0.18946813002946805,0.9884781177829836,0.5870931575914757,0.9730439867672014]<\/pre>\n
The output is:<\/p>\n
\"\"<\/p>\n
In the above code, we used the random function inside the for loop<\/a> to generate five random numbers. Then, we used the push method to add every value generated to the array. This how we create an array of random numbers.<\/p>\n
We created an array of floating-numbers, we can also create an array containing random numbers between any range. The following code shows how to do this.<\/p>\n
var arr = []; \r\nvar result;\r\nvar min = 50;\r\nvar max = 100;\r\n\r\nfor(var i=0;i<5;i++) { \r\nresult = Math.ceil(Math.random() * (max-min) + min); \r\narr.push(result) \r\n} \r\n\r\n\/\/ arr = [60,96,99,98,82]<\/pre>\n
The output is:<\/p>\n
\"Math<\/p>\n
In the above code, we used the maximum and minimum values to generate random numbers and then used the ceil function to convert the floating-point numbers to integers.<\/p>\n
Conclusion<\/h3>\n
Javascript<\/a> is a vast language that comes with many in-built functions and objects. One of these objects is math that has many properties and methods. One of these methods, the math random\u00a0 Javascript function, we discussed in this article with examples. The random function is helpful during programming and development in many ways such as random decision making, random array generation, identification code generation, etc. The random function is easy to learn and use. Using it with other methods of math object, we can extend its working to another useful level.<\/p>\n","protected":false},"excerpt":{"rendered":"
Javascript provides a vast amount of math-related functions. In this article, we will explain how to use Math Random in Javascript. These in-built functions and objects are very useful while programming and developing. In-built functions and objects reduce the work for the developers. Some of the most commonly used in-built javascript functions and objects are […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-1524","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"yoast_head":"\nMath Random in Javascript: generating random numbers - Copahost<\/title>\n<meta name=\"description\" content=\"Want to generate random numbers in javascript? This article explains with examples of how to use math random in Javascript. 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