JavaScript | Random
The Math.random() function is used to return a floating-point pseudo-random number between range [0,1) , 0 (inclusive) and 1 (exclusive). This random number can be scaled according to the desired range.
Syntax:
Math.random()
Example: This example uses Math.random() function to returns a random number.
<!DOCTYPE html> < html > < body > < h2 >Math.random()</ h2 > < p > Math.random() returns a random number between 0 and 1 </ p > < p id = "GFG" ></ p > <!-- Script to use Math.random() function --> < script > document.getElementById("GFG").innerHTML = Math.random(); </ script > </ body > </ html > |
Output:
Random Integers: The Math.random() method is used with Math.floor() function to return random integers.
Example:
<!DOCTYPE html> < html > < body > < center > < p > Math.floor(Math.random() * 11) returns a random integer between 0 and 10 (inclusive): </ p > < p id = "demo" ></ p > </ center > <!-- Script to use Math.random() function and Math.floor() function to return random integer --> < script > document.getElementById("demo").innerHTML = Math.floor(Math.random() * 11); </ script > </ body > </ html > |
Output:
Proper Random Function: JavaScript function always returns a random number between min and max where min is inclusive and max may be inclusive or exclusive both.
Example:
<!DOCTYPE html> < html > < body > < p > When you click the button it will give a random value between 0 and 9 both inclusive: </ p > < button onclick="document.getElementById('GFG') .innerHTML = getRndInteger (0, 10)">Try it</ button > < p id = "GFG" ></ p > <!-- Script to return random number between 0 and 10 --> < script > function getRndInteger(min, max) { return Math.floor(Math.random() * (max - min)) + min; } </ script > </ body > </ html > |
Output on first click:
Output on second click: