JavaScript vs C# LINQ: A Developer-Friendly Cheat Sheet 📃

If you're a C# developer learning JavaScript—or a JavaScript developer curious about LINQ in C#—this guide is for you. Let's compare some of the most common data transformation methods between JavaScript Arrays and C# LINQ.

🔁 Overview Table

Examples:

🍧 1. Filtering Items

C# LINQ

var adults = people.Where(p => p.Age >= 18);

JavaScript

const adults = people.filter(p => p.age >= 18);

🍧 2. Selecting/Projecting Fields

C# LINQ

var names = people.Select(p => p.Name);

JavaScript

const names = people.map(p => p.name);

🍧 3. Checking Conditions

C# LINQ

bool anyMinor = people.Any(p => p.Age < 18);
bool allAdults = people.All(p => p.Age >= 18);

JavaScript

const anyMinor = people.some(p => p.age < 18);
const allAdults = people.every(p => p.age >= 18);

🍧 4. Reducing/Aggregating Values

C# LINQ

int totalAge = people.Aggregate(0, (sum, p) => sum + p.Age);

JavaScript

const totalAge = people.reduce((sum, p) => sum + p.age, 0);

🍧 5. Sorting Items

C# LINQ

var sorted = people.OrderBy(p => p.Name).ThenBy(p => p.Age);

JavaScript

const sorted = people
  .sort((a, b) => a.name.localeCompare(b.name) || a.age - b.age);

🍧 6. Finding the First Match

C# LINQ

var firstAdult = people.FirstOrDefault(p => p.Age >= 18);

JavaScript

const firstAdult = people.find(p => p.age >= 18);

🌟 Final Thoughts

JavaScript and C# may look different on the surface, but their array and LINQ methods are quite similar under the hood. If you're transitioning between the two, keep this guide handy to translate concepts quickly!

If you found this helpful, consider supporting my work at ☕ Buy Me a Coffee.