# Number.MAX_VALUE and Number.MIN_VALUE define the outer bounds of the Number value set : Introduction « Number Data Type « JavaScript Tutorial

All numbers must fall between Number.MAX_VALUE and Number.MIN_VALUE.

When a calculation results in a number greater than Number.MAX_VALUE, it is assigned a value of Number.POSITIVE_INFINITY.

When a calculation results in a number less than Number.MIN_VALUE, it is assigned a value of Number.NEGATIVE_ INFINITY.

If a calculation returns an infinite value, the result cannot be used in any further calculations.

There is a special value for infinity named Infinity.

Number.POSITIVE_ INFINITY has a value of Infinity.

Number.NEGATIVE_INFINITY has a value of -Infinity.

A method can be used to determine if a number is finite.

```var iResult = iNum* some_really_large_number;
if (isFinite(iResult)) {
} else {
}
```
```The perils of Javascript - Number.MIN_VALUE
from lodge.stuart at gmail.com

Just spent some time debugging a problem....

I had a filter set up in my new player code on runsat - and when the filter was disabled I was setting
the filter limits to Number.MIN_VALUE and Number.MAX_VALUE.

I thought this would be fine because several site like
http://www.java2s.com/Tutorial/JavaScript/0100__Number-Data-Type/NumberMAXVALUEandNumberMINVALUEdefinetheouterboundsoftheNumbervalueset.htm say things like:

When a calculation results in a number greater than Number.MAX_VALUE, it is assigned a value of Number.POSITIVE_INFINITY.

When a calculation results in a number less than Number.MIN_VALUE, it is assigned a value of Number.NEGATIVE_ INFINITY.

However.... this is complete "codswollop" - actually MIN_VALUE is an epsilon value - it's the smallest positive fraction allowed in javascript - so it's not negative - in fact it's almost (but not quite) zero.

Looking around loads of sites contain big info on this!

Yikes!
```
 5.1.Introduction 5.1.1. Numbers 5.1.2. Number() Object 5.1.3. Variables are loosely typed. 5.1.4. Built-in Values 5.1.5. Special Numerical Values 5.1.6. Primitive and Reference Values 5.1.7. Primitive Types 5.1.8. The Undefined Type 5.1.9. The Null Type 5.1.10. The Boolean Type 5.1.11. The Number Type 5.1.12. Number.MAX_VALUE and Number.MIN_VALUE define the outer bounds of the Number value set 5.1.13. NaN stands for Not a Number 5.1.14. JavaScript primitive values, Booleans, numbers, and strings, are pseudo-objects 5.1.15. Reference Types