Today I asked AI to create a JavaScript to C# cheat sheet in markdown format, since I come from a strong C# background and I'm working towards improving my JavaScript skills. When I don't know how to do something the JavaScript way, I find it helpful to think in terms of C# and then translate.
This cheat sheet helps developers transition from JavaScript to C# by comparing syntax and concepts side by side.
📌 Variable Declaration
| JavaScript | C# |
let x = 5; | int x = 5; |
const name = "John"; | const string name = "John"; |
var isActive = true; | bool isActive = true; |
🔢 Data Types
| JavaScript | C# |
| Number | int, float, double |
| String | string |
| Boolean | bool |
| Object | class |
| Array | array or List |
| null / undefined | null |
🔁 Loops
| JavaScript | C# |
for (let i = 0; i < 10; i++) | for (int i = 0; i < 10; i++) |
while (x < 10) | while (x < 10) |
do { ... } while (x < 10) | do { ... } while (x < 10); |
for (let item of array) | foreach (var item in array) |
✅ Conditionals
| JavaScript | C# |
if (x > 5) { ... } | if (x > 5) { ... } |
else if (x < 3) | else if (x < 3) |
else | else |
switch (value) | switch (value) |
📦 Functions / Methods
| JavaScript | C# |
function greet(name) { ... } | void Greet(string name) { ... } |
const add = (a, b) => a + b; | int Add(int a, int b) => a + b; |
return value; | return value; |
🧱 Classes
| JavaScript | C# |
class Person { constructor(name) { this.name = name; } } | class Person { public string Name; public Person(string name) { Name = name; } } |
🔧 Properties and Methods
| JavaScript | C# |
this.name | this.Name |
getName() | GetName() |
🧪 Equality
| JavaScript | C# |
== | == |
=== | == (type-safe) |
!= | != |
📚 Miscellaneous
| JavaScript | C# |
console.log("Hi") | Console.WriteLine("Hi"); |
typeof x | x.GetType() |
JSON.stringify(obj) | JsonConvert.SerializeObject(obj) (via Newtonsoft.Json) |
Feel free to expand this with more advanced topics like async/await, LINQ, events, and delegates!
