**This article will explain what absolute values are, how they are used, and how the JavaScript Math.abs() function can be used to calculate the absolute value of a number.**

## What is the ‘Absolute Value’ of a Number?

The **absolute value** of a number is that number’s value – without any regard to its **sign**.

A numbers **sign** determines whether it is ** positive** or

**–**

*negative**it’s the*. So, the absolute value of a number is never

**–**symbol before a negative number*negative*.

*Consider the absolute value of a number that numbers distance from*

**0**.The absolute value of a number is may also be referred to in mathematics and other programming languages as the **modulus** or **magnitude** of a number.

*Here are some examples to illustrate:*

Number | Absolute/Modulus Value |
---|---|

4 | 4 |

-4 | 4 |

-2.5 | 2.5 |

–x |
x |

When writing mathematical equations, the absolute value is written as **| x|** (two vertical bars surrounding the number we are taking the absolute value of).

## How/Why are Absolute Values Used?

**Absolute values** are most often used when dealing with distances in mapping/geography, and physics calculations for simulations and games.

When calculating direction or speed, you’re measuring that vector in relation to a fixed point. Movement in one direction may be considered positive, and movement in the opposite direction negative.

In the above scenario, if you’ve moved 30m to the *left* your position from the fixed point is -30m. However, you can’t be a *negative* distance from something – there’s no such thing as a *negative kilometer* – so to find the *distance* from the fixed point you’d use the **absolute value** of the new position:

|-30| = 30

**This may seem like a trivial difference – but it is important when calculating an object’s position and movement – if you want to make video games or 3D simulations, you’ll be using it a lot!**

## JavaScript *Math.abs()* Function Syntax

The absolute value of a number can be calculated in JavaScript using the *Math.abs()* function. The syntax is as follows:

Math.abs(NUMBER)

Note that:

**NUMBER**can be any numerical value- The function will return the absolute value of the number

*Math.abs()* Examples

Below is some example usage of *Math.abs()* – with the expected results:

Math.abs(-3); // 3 Math.abs(3); // 3 Math.abs('-3'); // 3 - The string was successfully parsed as a number Math.abs(null); // 0 - null has a zero absolute value Math.abs(''); // 0 - as does an empty string Math.abs([]); // 0 - as does an empty array Math.abs([3]); // 3 - If an array has a single numeric member, the absolute value of that member will be returned Math.abs([3, 4]); // NaN - If an array with more than one member is passed, even if they are all numeric, NaN will be returned Math.abs({}); // NaN - Objects cannot be parsed as numbers, so NaN will be returned Math.abs('string'); // NaN - If a string which cannot be parsed as a number is passed, NaN is returned Math.abs(); // NaN - If no value is passed, NaN is returned

If the value passed to *Math.abs()* cannot be coerced to a number, the value **NaN** (Not a Number) will be returned instead.