How to Use the Number Object
Examples
Using the Number object to assign values to numeric variables
The following example uses the Number
object's properties to assign values to several numeric variables:
const biggestNum = Number.MAX_VALUE; const smallestNum = Number.MIN_VALUE; const infiniteNum = Number.POSITIVE_INFINITY; const negInfiniteNum = Number.NEGATIVE_INFINITY; const notANum = Number.NaN;
Integer range for Number
The following example shows the minimum and maximum integer values that can be represented as Number
object.
const biggestInt = Number.MAX_SAFE_INTEGER; // (2**53 - 1) => 9007199254740991 const smallestInt = Number.MIN_SAFE_INTEGER; // -(2**53 - 1) => -9007199254740991
When parsing data that has been serialized to JSON, integer values
falling outside of this range can be expected to become corrupted when
JSON parser coerces them to Number
type.
A possible workaround is to use String
instead.
Larger numbers can be represented using the BigInt
type.
Using Number() to convert a Date object
The following example converts the Date
object to a numerical value using Number
as a function:
const d = new Date("1995-12-17T03:24:00"); console.log(Number(d));
This logs 819199440000
.
Convert numeric strings and null to numbers
Number("123"); // 123 Number("123") === 123; // true Number("12.3"); // 12.3 Number("12.00"); // 12 Number("123e-1"); // 12.3 Number(""); // 0 Number(null); // 0 Number("0x11"); // 17 Number("0b11"); // 3 Number("0o11"); // 9 Number("foo"); // NaN Number("100a"); // NaN Number("-Infinity"); // -Infinity