JavaScript Number

In JavaScript, the Number data type represents both integers and floating-point (decimal) numbers. It is a fundamental type used for mathematical calculations and numeric logic.

What is a Number in JavaScript?

JavaScript uses a single number type based on the IEEE 754 double-precision 64-bit binary format. There is no separate type for integers or floats; both are considered as Number.

Example:

Valid Numeric Representations

• Decimal: 42
• Hexadecimal: 0x2A (equals 42)
• Exponential: 2e3 (equals 2000)
• Octal (ES6+): 0o52 (equals 42)
• Binary (ES6+): 0b101010 (equals 42)

Type Checking

Number Precision

JavaScript can handle up to 15 digits of precision.

Common Number Methods

1. toFixed(n) - Returns a string with n digits after the decimal point.

2. toString() - Converts the number to a string.

3. toExponential() - Returns a string in exponential notation.

4. toPrecision() - Formats a number to a specified length.

Number Constants

• Number.MAX_VALUE: Largest possible number
• Number.MIN_VALUE: Smallest positive number
• Number.POSITIVE_INFINITY: Infinity
• Number.NEGATIVE_INFINITY: -Infinity
• Number.NaN: "Not a Number"

Example:

Special Numeric Values

1. Infinity and -Infinity

2. NaN (Not a Number) Occurs when a numeric operation fails.

Number Conversion

• Using Number()

• Using parseInt() and parseFloat()

Comparing Numbers

Key Takeaways

• JavaScript uses a single Number type for both integers and floats.
• Special values include NaN, Infinity, and constants like MAX_VALUE.
• Methods like toFixed(), toPrecision(), and toExponential() help format numbers.
• Use parseInt() and parseFloat() to convert strings to numbers.
• Always validate numeric operations to avoid unexpected NaN results.