Flash cards
Review the key moves
What is the main idea behind JavaScript Number Properties?
Lesson checks
Practice each idea before moving on
Short Mimo-style checks built from this lesson's code, terms, and sequence.
Which statement best captures the main point of this lesson?
Complete the missing token from the example code.
___ x = Number.EPSILON;Put the learning moves in the order that makes the concept easiest to apply.
Number Properties
| Number.EPSILON Number.MAX_VALUE Number.MIN_VALUE | Number.MAX_SAFE_INTEGER Number.MIN_SAFE_INTEGER Number.POSITIVE_INFINITY Number.NEGATIVE_INFINITY Number.NaN |
|---|
JavaScript EPSILON
Number.EPSILON is the difference between the smallest floating point number greater than 1 and 1.
Example
let x = Number.EPSILON;Number.EPSILON is an ES6 feature.
It does not work in Internet Explorer.
JavaScript MAX_VALUE
Number.MAX_VALUE is a constant representing the largest possible number in JavaScript.
Example
let x = Number.MAX_VALUE;Number Properties Cannot be Used on Variables
Number properties belong to the JavaScript Number Object .
These properties can only be accessed as Number.MAX_VALUE .
Using x.MAX_VALUE, where x is a variable or a value, will return undefined :
Example
let x = 6;
x.MAX_VALUEJavaScript MIN_VALUE
Number.MIN_VALUE is a constant representing the lowest possible number in JavaScript.
Example
let x = Number.MIN_VALUE;Minimum and Maximum Safe Integers
ES6 added max and min properties to the Number object:
- Number.MAX_SAFE_INTEGER
- Number.MIN_SAFE_INTEGER
JavaScript MIN_SAFE_INTEGER
Number.MIN_SAFE_INTEGER represents the minimum safe integer in JavaScript.
Number.MIN_SAFE_INTEGER is -(2 53 - 1).
Example
let x = Number.MIN_SAFE_INTEGER;JavaScript MAX_SAFE_INTEGER
Number.MAX_SAFE_INTEGER represents the maximum safe integer in JavaScript.
Number.MAX_SAFE_INTEGER is (2 53 - 1).
Example
let x = Number.MAX_SAFE_INTEGER;JavaScript POSITIVE_INFINITY
Example
let x = Number.POSITIVE_INFINITY;JavaScript NEGATIVE_INFINITY
Example
let x = Number.NEGATIVE_INFINITY;JavaScript NaN - Not a Number
NaN is a JavaScript reserved word for a number that is not a legal number.
Examples
let x = Number.NaN;Safe integers are all integers from -(2 53 - 1) to +(2 53 - 1). This is safe: 9007199254740991. This is not safe: 9007199254740992.