Mastering Number Methods in JavaScript

Number Methods in JavaScript

JavaScript provides several built-in methods to work with numbers effectively. These methods allow you to perform operations like formatting, rounding, parsing, and validating numbers.

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1. Converting Numbers

A. toString()

Converts a number to a string.

const num = 123;
console.log(num.toString()); // Output: "123"
console.log((456).toString()); // Output: "456"

B. toFixed(digits)

Formats a number with a fixed number of decimal places.

const num = 3.14159;
console.log(num.toFixed(2)); // Output: "3.14"
console.log(num.toFixed(4)); // Output: "3.1416"

C. toExponential(digits)

Returns the number in exponential notation.

const num = 12345;
console.log(num.toExponential(2)); // Output: "1.23e+4"

D. toPrecision(digits)

Formats a number to a specified total length (including decimals).

const num = 123.456;
console.log(num.toPrecision(4)); // Output: "123.5"
console.log(num.toPrecision(6)); // Output: "123.456"

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2. Parsing and Validating Numbers

A. parseInt(string, radix)

Parses a string into an integer.

console.log(parseInt("123")); // Output: 123
console.log(parseInt("101", 2)); // Output: 5 (binary to decimal)

B. parseFloat(string)

Parses a string into a floating-point number.

console.log(parseFloat("3.14")); // Output: 3.14
console.log(parseFloat("123abc")); // Output: 123

C. Number.isInteger(value)

Checks if a value is an integer.

console.log(Number.isInteger(123)); // Output: true
console.log(Number.isInteger(3.14)); // Output: false

D. Number.isFinite(value)

Checks if a value is a finite number.

console.log(Number.isFinite(123)); // Output: true
console.log(Number.isFinite(Infinity)); // Output: false

E. Number.isNaN(value)

Checks if a value is NaN (Not-a-Number).

console.log(Number.isNaN(NaN)); // Output: true
console.log(Number.isNaN(123)); // Output: false

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3. Rounding Numbers

A. Math.round()

Rounds a number to the nearest integer.

console.log(Math.round(4.5)); // Output: 5
console.log(Math.round(4.4)); // Output: 4

B. Math.ceil()

Rounds a number up to the next integer.

console.log(Math.ceil(4.1)); // Output: 5

C. Math.floor()

Rounds a number down to the previous integer.

console.log(Math.floor(4.9)); // Output: 4

D. Math.trunc()

Removes the decimal part of a number.

console.log(Math.trunc(4.9)); // Output: 4

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4. Generating Random Numbers

A. Math.random()

Generates a random number between 0 (inclusive) and 1 (exclusive).

console.log(Math.random()); // Output: A random number between 0 and 1

To generate a random number within a range:

const min = 1;
const max = 10;
const random = Math.floor(Math.random() * (max - min + 1)) + min;
console.log(random); // Output: A random number between 1 and 10

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5. Other Useful Number Methods

A. Math.abs()

Returns the absolute value of a number.

console.log(Math.abs(-5)); // Output: 5

B. Math.pow(base, exponent)

Returns the base raised to the power of the exponent.

const num = 123;
console.log(num.toString()); // Output: "123"
console.log((456).toString()); // Output: "456"

C. Math.sqrt()

Returns the square root of a number.

const num = 3.14159;
console.log(num.toFixed(2)); // Output: "3.14"
console.log(num.toFixed(4)); // Output: "3.1416"

D. Math.max() and Math.min()

Finds the maximum or minimum value among a set of numbers.

const num = 12345;
console.log(num.toExponential(2)); // Output: "1.23e+4"

E. Math.sign()

Returns the sign of a number (-1, 0, or 1).

const num = 123.456;
console.log(num.toPrecision(4)); // Output: "123.5"
console.log(num.toPrecision(6)); // Output: "123.456"

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6. Summary

• JavaScript provides a wide range of methods to work with numbers, from conversion to complex mathematical operations.
• The Math object contains utility functions for advanced calculations.
• Use these methods to handle rounding, parsing, formatting, and generating numbers efficiently.

By mastering these number methods, you can handle various numerical operations in JavaScript with ease.

Hi, I'm Abhay Singh Kathayat!
I am a full-stack developer with expertise in both front-end and back-end technologies. I work with a variety of programming languages and frameworks to build efficient, scalable, and user-friendly applications.
Feel free to reach out to me at my business email: kaashshorts28@gmail.com.

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