Efficient code is not only about what it does but also how fast and resource-effectively it does it. This document explores best practices for writing efficient JavaScript and TypeScript code, touching upon recursive functions, algorithm choice, and optimization techniques.

Efficient Function Execution

Good Example: Efficient Function

function quickSort(data: number[]): number[] {
  // Efficient sorting logic
}

Bad Example: Inefficient Function

function slowSort(data: number[]): number[] {
  // Inefficient sorting logic with unnecessary complexity
}

In the context of code efficiency and best practices, the two provided functions demonstrate how different approaches to a similar problem can affect readability and maintainability:

Good Example: Using a Mapping Object

type IconFillColor = "primary" | "secondary";

const iconFillColors: Record<IconFillColor, string> = {
  "primary": "#000000",
  "secondary": "#808080",
};

export function getIconFillColor(fillColor: IconFillColor) {
  return iconFillColors[fillColor] ?? throw new Error(`Invalid fill color: ${fillColor}`);
}

Bad Example: Using a Switch Statement

type IconFillColor = "primary" | "secondary";

export function getIconFillColor(fillColor: IconFillColor) {
  switch (fillColor) {
    case "primary":
      return "#000000";
    case "secondary":
      return "#808080";
    default:
      throw new Error(`Invalid fill color: ${fillColor}`);
  }
}

The “good” example uses a mapping object which is more succinct and easier to manage, especially when dealing with a large number of cases. It avoids the boilerplate of a switch statement and makes the function shorter and cleaner.


Simplifying Complex Logic with Design Patterns 💥

Certainly, using multiple if conditions can make code hard to read and maintain. A better approach might be to encapsulate each condition in its own function or use a strategy pattern. Here’s a comparison:

Bad Example: Multiple If Conditions

function processRequest(type) {
  if (type === "create") {
    // create logic
  } else if (type === "update") {
    // update logic
  } else if (type === "delete") {
    // delete logic
  }
  // ...more conditions...
}

Good Example: Strategy Pattern with Functions

const operations = {
  create: (data) => {
    // create logic
  },
  update: (data) => {
    // update logic
  },
  delete: (data) => {
    // delete logic
  },
  // ...more operations...
};

function processRequest(type, data) {
  const operation = operations[type];
  if (operation) {
    operation(data);
  } else {
    throw new Error("Invalid operation type");
  }
}

In the “good” example, each operation is encapsulated in its own function within a operations object. This not only makes the processRequest function cleaner but also simplifies adding or modifying operations in the future.

This is just one way to approach the problem. Other design patterns can also be used to simplify complex logic.

Tips for Writing Efficient TypeScript Code

Leverage TypeScript’s type system for performance and safety.

Good Example: Leveraging TypeScript’s Types for Performance

interface Comparable {
  compareTo(other: Comparable): number;
}

// Implementing an efficient sorting algorithm using the Comparable interface

Bad Example: Ignoring TypeScript’s Type System

// Using 'any' type reduces the ability to optimize and can lead to runtime errors
function sortItems(items: any[]): any[] {
  // Sorting logic without type checks
}

Recursive Functions and Performance

Recursion can be elegant but sometimes comes at the cost of performance.

Good Example: Tail-Recursive Optimization

function factorial(n, accumulator = 1) {
  if (n === 0) {
    return accumulator;
  }
  return factorial(n - 1, n * accumulator);
}

Bad Example: Non-Optimized Recursive Function

function factorial(n) {
  if (n === 1) {
    return 1;
  }
  return n * factorial(n - 1); // Potential stack overflow for large n
}

Choosing the Right Algorithm

The efficiency of an algorithm significantly impacts performance, especially with large datasets.

Good Example: Efficient Algorithm Selection

// Binary search for sorted arrays
function binarySearch(array: number[], target: number): boolean {
  // Binary search logic
}

Bad Example: Inefficient Algorithm Selection

// Linear search on a sorted array is less efficient
function linearSearch(array: number[], target: number): boolean {
  // Linear search logic
}

Conclusion

Embracing efficient coding practices in JavaScript and TypeScript not only streamlines your development process but also enhances the performance and maintainability of your applications. By utilizing design patterns, optimizing algorithms, and employing the power of TypeScript’s type system, you can write cleaner, more effective code. Always strive to balance clarity with performance, and remember that the best code is not only functional but also intuitive and accessible to other developers in the long term.