significant digits, it cannot always exactly represent real numbers,

including fractions.

This becomes an issue when comparing or formatting numbers. For example:

console.log(0.2 + 0.1 === 0.3); // displays false

console.log(0.94 - 0.01); // displays 0.9299999999999999

As a result, a routine such as the toFixed() method should be used to

round numbers whenever they are formatted for output.

Numbers may be specified in any of these notations:

JavaScript

34.5; // a floating-point number

3.45e2; // another floating-point, equivalent to 345

0b1011; // a binary integer equal to 11

0o377; // an octal integer equal to 255

...

// ... letters A-F may be upper or lowercase

There is also a numeric separator, _ (the underscore), introduced in

ES2021:

// Note: Wikipedia syntax does not support numeric separators yet

1_000_000_000; // Used with big numbers

1_000_000.5; // Support with decimals

1_000e1_000; // Support with exponents

// Support with binary, octals and hex

0b0000_0000_0101_1011;

0o0001_3520_0237_1327;

0xFFFF_FFFF_FFFF_FFFE;

start or end

identifier)

12_; // Syntax error (cannot be at the end of numbers)

the decimal point)

12._0; // Syntax error

put a separator at the start)

separator at a time is allowed

The extents +∞, −∞ and NaN (Not a Number) of the number type may be

obtained by two program expressions:

instance)