20241121_1 Numbers

The maximum number of decimals is 17.

Adding Numbers and Strings

 JavaScript  interpreter works from left to right.  ex) number + number +string  case, both numbers added andthen add string

NaN - Not a Number

NaN + number = NaN, NaN + string ="NaNstring"

Infinity

calculate a number outside the largest possible number.

Hexadecimal

number.toString( Number system ) : 

 

BigInt

JavaScript can only safely represent integers:

Up to 9007199254740991 +(253-1)   Down to -9007199254740991 -(253-1).

How to Create a BigInt

BigInt(num); or let x = 12345.......n;

Arithmetic between a BigInt and a Number is not allowed

 

Minimum and Maximum Safe Integers

Number.MAX_SAFE_INTEGER : Integer max value

Number.MIN_SAFE_INTEGER  : Integer min value

Number.isInteger(number) : returns true if the argument is an integer.

Number.isSafeInteger(number) : r eturns true if the argument is a safe integer.

Number.MAX_VALUE : the largest possible number in JavaScript.

Number.MIN_VALUE  : the lowest possible number in JavaScript.

Number.POSITIVE_INFINITY

Number.NEGATIVE_INFINITY

Number Methods

toString()	Returns a number as a string
toExponential()	Returns a number written in exponential notation
toFixed()	Returns a number written with a number of decimals
toPrecision()	Returns a number written with a specified length
valueOf()	Returns a number as a number

Converting Variables to Numbers

Number()	Returns a number converted from its argument.
parseFloat()	Parses its argument and returns a floating point number
parseInt()	Parses its argument and returns a whole number

 

function isNaN() : find out if a value is a not a number