A brief overview of numbers

13 сентября 2025 г.

A number in a program is a numeric literal.

Types

Integer literals

1) Decimal numbers- 3, 0, 1000

2) Hexadecimal literals — start with 0x or 0X, followed by hexadecimal digits.

3) In ES6 and later — binary and octal literals with prefixes 0b and 0o (0B and 0O)

Floating-point numbers: 2.18, .676, 8, 07e12, 1.7e-34.

Arithmetic operations

• Addition: +
• Subtraction: -
• Multiplication: *
• Division: /
• Modulo division (remainder after division): %
• Exponentiation (ES6): **
• The Math object provides more advanced operations. It does not accept BigInt operands.

Overflow / Infinity

Overflow happens when a result exceeds the largest representable number (positive or negative). It becomes Infinity or -Infinity.

Underflow

Loss of precision occurs when a result is closer to zero than the smallest representable number. In this case, 0 is returned.If it happens with a negative number, -0 is returned.

Positive zero and negative zero are equal in strict comparison, but differ in division behavior.

Division by zero

Division by zero returns Infinity or -Infinity.Exception: 0 / 0 returns NaN (Not a Number).

NaN (not a number)

Occurs in cases such as:

• 0 / 0
• Infinity / Infinity
• square root of a negative number
• arithmetic with non-numeric operands

NaN is not equal to anything — even itself.

Methods

To check if a value is NaN, use:

• Number.isNaN()
• or isNaN()

Number.isFinite() returns true if the value is a number and not Infinity, -Infinity, or NaN.

isFinite(number) returns true if the value can be converted to a finite number or already is one.

BigInt

A numeric type for integers.

It is written as a number with an n suffix and may use 0o, 0x, or 0b prefixes.

BigInt() converts a number into a BigInt value.

Arithmetic works similarly to normal numbers, but operations between Number and BigInt are not allowed.

Comparisons between normal numbers and BigInt values work correctly.