JavaScript - Math
Selected Methods
| Method | Description |
|---|---|
| abs | Returns the absolute value of a number. i.e. it returns the number if the number is positive and -1 × the number if the number is negative. |
| ceil | Returns the smallest whole number greater than or equal to a number. |
| floor | Returns the largest whole number less than or equal to a number. |
| max | Returns the largest of its number arguments. |
| min | Returns the smallest of its number arguments. |
| random | Returns a random number between 0 and 1 which can be 0 but not 1. |
| round | Returns the nearest whole number. |
abs
The abs method returns the absolute value of a number. i.e. it returns the number if the number is positive and -1 × the number if the number is negative.
console.log(Math.abs(5)); // 5
console.log(Math.abs(-8)); // 8
ceil
The ceil method returns the smallest whole number greater than or equal to a number.
console.log(Math.ceil(5.2)); // 6
console.log(Math.ceil(24)); // 24
console.log(Math.ceil(-3.8)); // -3
floor
The floor method returns the largest whole number less than or equal to a number.
console.log(Math.floor(5.2)); // 5
console.log(Math.floor(24)); // 24
console.log(Math.floor(-3.8)); // -4
max
The max method returns the largest of its number arguments.
console.log(Math.max(3, 11, 7, 2)); // 11
console.log(Math.max(-8, 3)); // 3
min
The min method returns the smallest of its number arguments.
console.log(Math.min(3, 11, 7, 2)); // 2
console.log(Math.min(-8, 3)); // -8
random
The random method returns a random number between 0 and 1 which can be 0 but not 1.
console.log(Math.random());
// e.g. 0.6517522458452731
Multiply the random number to change the range of possible numbers.
console.log(10 * Math.random());
// 0 ≤ number < 10
console.log(42 * Math.random());
// 0 ≤ number < 42
Add to the random number to change the range of possible numbers.
console.log(10 + Math.random());
// 10 ≤ number < 11
console.log(10 + 42 * Math.random());
// 10 ≤ number < 52
Use Math.floor to generate whole numbers.
console.log(Math.floor(10 + 2 * Math.random()));
// 10 ≤ number ≤ 11
console.log(Math.floor(10 + 42 * Math.random()));
// 10 ≤ number ≤ 51
round
The round method returns the nearest whole number.
console.log(Math.round(3.2)); // 3
console.log(Math.round(3.5)); // 4
console.log(Math.round(3.9)); // 4
Further Help
You can find an excellent reference of properties and methods on the Mozilla Developer Network Math object page.