JavaScript to Generate a Random Number Between X and Y

By Stephen Bucaro

You can use the JavaScript Math object's .random() method to generate a random number between two values, but because it returns a (pseudo) random floating-point number between 0 and 1 (but not including 1), you'll need to perform some additional operations on it to scale it to your required range.

To generate a random integer between two values x and y use the code shown below:

Math.floor((Math.random() * y) + x);

x being the lowest value, and y being the highest value.

For example if you wanted to generate a random integer between 1 and 8, you would use:

Math.floor((Math.random() * 8) + 1);

The Math.floor() function returns the largest integer less than or equal to the passed argument.

If the lowest random integer that you require is 0, you can simplify the statement as shown below:

Math.floor(Math.random() * max);

To generate a random floating-point number between two values x and y you would use the code shown below:

return Math.random() * (max-min) + min;

More Java Script Code:
• Regular Expression Position Matching
• Java Script to Get Selected Item from Select List Option Group
• Java Script Random Password Generator
• Code for Java Script Cube / Box Volume Calculator
• Replace Drop-down with Drag-and-drop
• Prevent Automated Form Submissions With Java Script
• Basic State Machines
• Regular Expressions Subexpressions
• Introduction to JavaScript Programming
• JavaScript 24-Hour Trainer

RSS Feed

 Follow @Stephen Bucaro

 General Web Design
 HTML Quick Reference
 CSS Quick Reference
 Java Script Quick Reference
 HTML Design
 Graphics Design
 Easy Cascading Style Sheets
 Easy Java Script Code
 Web Design Tools
 Coding Issues