Online Swift CLI Runner

Try out Swift commands in an Xcode-free CLI interface—perfect for quick experiments.

Version

Sample

🚀 3,755 total executions (480 this month)

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🍎 About This Swift Online Executor

The CodeUtility Swift Executor lets you write and run Swift code directly in your browser — no Xcode, SDK, or macOS setup required. It runs real Swift compilers in isolated sandboxes to deliver accurate, native Swift behavior.

This tool supports multiple Swift versions — 5.7, 5.9, and the latest release — giving you the flexibility to explore new language features and maintain compatibility with older Swift codebases.

It’s perfect for developers learning Swift syntax, testing algorithms, or experimenting with code for iOS, macOS, and server-side Swift without needing to install local tools or simulators.

Each snippet runs securely in a containerized Swift environment, ensuring real compiler feedback and safe code execution.

💡 How to Use This Tool

1. Choose a Swift version from the dropdown above the editor (5.7, 5.9, or Latest).
2. Write or paste your Swift code directly into the editor area.
3. Click Run to compile and execute your code — the output will appear instantly in the console below.
4. While your code runs, a Stop button appears — click it to terminate execution early.
5. Use Fix Code to automatically correct syntax or formatting errors.
6. After fixing, a Fixes button appears — click it to review recent corrections.
7. You can also Upload local Swift files or Download your code for backup or sharing.
8. Each execution is limited to 20 seconds for consistent performance and system stability.

🧠 Tip: The Swift Executor supports modern Swift syntax, optionals, structs, enums, and protocol-oriented programming — ideal for learning, experimenting, or testing Swift code quickly online.

💡 Swift Basics Guide for Beginners

1. Declaring Variables and Constants

Use var for variables and let for constants in Swift.

var age = 30
let pi = 3.14159
var name = "Alice"
let isActive = true

// Constants cannot be reassigned
// pi = 3.14 // ❌ Error

2. Conditionals (if / switch)

Use if, else if, else for logic, and switch for multiple branches.

let number = 2
if number == 1 {
    print("One")
} else if number == 2 {
    print("Two")
} else {
    print("Other")
}

switch number {
case 1:
    print("One")
case 2:
    print("Two")
default:
    print("Other")
}

3. Loops

Swift supports for-in, while, and repeat-while loops.

for i in 0..<3 {
    print(i)
}

var n = 3
while n > 0 {
    print(n)
    n -= 1
}

4. Arrays

Arrays store ordered collections of values.

var numbers = [10, 20, 30]
print(numbers[1])

5. Array Manipulation

Use array methods like append and removeLast.

var nums = [1, 2, 3]
nums.append(4)
nums.removeLast()

for n in nums {
    print(n)
}

6. Console Input/Output

Use print() for output. Input requires additional work in Swift Playgrounds or Xcode.

let name = "Alice"
print("Hello, \(name)")

7. Functions

Define reusable functions with parameters and return values.

func add(a: Int, b: Int) -> Int {
    return a + b
}

print(add(a: 3, b: 4))

8. Dictionaries

Dictionaries store key-value pairs.

var ages = ["Alice": 30]
print(ages["Alice"] ?? 0)

9. Error Handling

Swift uses do-catch for error handling.

enum MyError: Error {
    case runtimeError(String)
}

do {
    throw MyError.runtimeError("Something went wrong")
} catch let error {
    print(error)
}

10. File I/O

Swift uses FileManager or String methods for file I/O.

let text = "Hello File"
try text.write(toFile: "file.txt", atomically: true, encoding: .utf8)
let content = try String(contentsOfFile: "file.txt")
print(content)

11. String Manipulation

Use methods like count, contains, uppercased(), etc.

let text = "Hello World"
print(text.count)
print(text.contains("World"))
print(text.uppercased())

12. Classes & Objects

Swift supports OOP using class and init.

class Person {
    var name: String
    init(name: String) {
        self.name = name
    }
    func greet() {
        print("Hi, I'm \(name)")
    }
}

let p = Person(name: "Alice")
p.greet()

13. Optionals

Swift uses ? and ! to handle optional values.

var name: String? = "Alice"
print(name ?? "Unknown")

if let unwrappedName = name {
    print(unwrappedName)
}