JavaScript Utilities.md

JavaScript Utilities

This document provides a collection of useful JavaScript functions for common programming tasks. These functions are designed to be simple, reusable, and beginner-friendly.

---

Table of Contents

1. Unique ID Generator
2. Browser Specifications
3. Base Converter

---

1. Unique ID Generator

Generates a unique alphanumeric string with an optional specified length.

Function

function unique_id(length = 32) {
  let result = '';
  let characters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
  // Start with a lowercase letter
  result += characters.charAt(Math.floor(Math.random() * 26));
  // Continue with full character set
  for (let i = 1; i < length; i++) {
    result += characters.charAt(Math.floor(Math.random() * characters.length));
  }
  return result;
}

Explanation

• Purpose: Generate a unique identifier, useful for session tokens, element IDs, or other cases requiring uniqueness.
• Starts with Lowercase Letter: Ensures the first character is a lowercase letter, useful for HTML id attributes that should not start with a number.

Example Usage

console.log(unique_id()); // Example: "aP9X7kL4w0M6Z2j8n5Q3G1v9C6L7T5a"
console.log(unique_id(16)); // Example: "bX8Z6K4M9N1W3T2Y"

---

2. Browser Specifications

Returns an object containing details about the user's browser capabilities and environment.

Function

function browserSpecs() {
  let res = {};
  res.navigator = Boolean(Navigator);
  res.storage = Boolean(Storage);
  res.worker = Boolean(Worker);
  res.eventSource = Boolean(EventSource);
  res.serviceWorker = Boolean(navigator.serviceWorker);

  res.cookieEnabled = navigator.cookieEnabled;
  res.platform = navigator.platform;
  res.language = navigator.language;

  return res;
}

Explanation

• Purpose: Determine the browser's capabilities, such as support for web workers, storage, or service workers.
• Properties Returned:
  • navigator, storage, worker, eventSource, serviceWorker: Boolean values indicating browser feature support.
  • cookieEnabled: Whether cookies are enabled.
  • platform: The user's operating system or device type.
  • language: The preferred language set in the browser.

Example Usage

console.log(browserSpecs());
/*
Example Output:
{
  navigator: true,
  storage: true,
  worker: true,
  eventSource: true,
  serviceWorker: true,
  cookieEnabled: true,
  platform: "Win32",
  language: "en-US"
}
*/

---

3. Base Converter

Converts numbers between different bases (e.g., decimal to hexadecimal, hexadecimal to decimal).

Function

function baseConverter(num, base, newBase) {
  const substitute = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'];

  if (newBase > base) {
    let remainders = [];
    let last = false;

    while (Math.floor(num / newBase) !== 0 || last !== true) {
      if (Math.floor(num / newBase) === 0) {
        last = true;
      }
      remainders.push(substitute[num % newBase]);
      num = Math.floor(num / newBase);
    }

    return remainders.reverse().join('');
  } else {
    let letters = num.split('').reverse();
    let numbers = [];

    letters.forEach((item, i) => {
      numbers.push(substitute.indexOf(item.toUpperCase()) * Math.pow(base, i));
    });

    return numbers.reduce((a, b) => a + b, 0);
  }
}

Explanation

• Purpose: Convert numbers between different bases, such as binary, decimal, hexadecimal, etc.
• Supports Two Cases:
  1. Base Expansion: Converts numbers to a higher base (e.g., decimal to hexadecimal).
  2. Base Reduction: Converts numbers from a higher base to a lower base (e.g., hexadecimal to decimal).
• Substitute Array: Maps digits to characters for bases above 10 (e.g., A for 10, B for 11).

Example Usage

// Convert 1250 (decimal) to hexadecimal
console.log(baseConverter(1250, 10, 16)); // Output: "4E2"

// Convert "4E2" (hexadecimal) to decimal
console.log(baseConverter('4E2', 16, 10)); // Output: 1250

Limitations

• Assumes input validity; invalid characters or bases are not handled.
• Supports bases up to 36 due to the English alphabet limit.

---

Best Practices

1. Error Handling:

   • Add input validation to ensure valid numbers and bases.
   • Handle edge cases like zero or negative numbers in the base converter.

2. Browser Capability Checks:

   • Expand browserSpecs to include newer features like WebAssembly or WebRTC.

3. ID Uniqueness:

   • For critical use cases (e.g., session tokens), consider using a UUID library like uuid for better guarantees.

4. Optimizing Base Conversion:

   • Use built-in JavaScript functions like parseInt and toString for simple conversions:

     console.log(parseInt('4E2', 16)); // 1250
     console.log((1250).toString(16).toUpperCase()); // "4E2"

---

Conclusion

These utility functions provide practical solutions for common JavaScript tasks:

• Generating unique IDs for dynamic elements or identifiers.
• Retrieving browser specifications for feature detection.
• Converting numbers between bases for data manipulation or formatting.