Why SwiftUI is the modern UI framework in iOS Swift

Introduction

SwiftUI helps you build app screens faster and easier. It uses simple code that updates the screen automatically when data changes.

When you want to create a new iPhone or iPad app with less code.

When you want your app to look good on all Apple devices without extra work.

When you want your app to update its screen smoothly when users interact.

When you want to write code that is easy to read and maintain.

When you want to use the latest Apple tools and features for building apps.

Syntax

iOS Swift

import SwiftUI

struct ContentView: View {
    var body: some View {
        Text("Hello, SwiftUI!")
            .padding()
    }
}

The View protocol defines a UI component.

The body property describes what the UI looks like.

Examples

Shows simple text on the screen.

iOS Swift

Text("Welcome to SwiftUI")

Stacks two text lines vertically.

iOS Swift

VStack {
    Text("Line 1")
    Text("Line 2")
}

A button that prints a message when tapped.

iOS Swift

Button("Tap me") {
    print("Button tapped")
}

Sample App

This app shows a button and a text label. Each time you tap the button, the number updates automatically on screen.

iOS Swift

import SwiftUI

struct ContentView: View {
    @State private var count = 0

    var body: some View {
        VStack(spacing: 20) {
            Text("You tapped \(count) times")
                .font(.title)
            Button("Tap me") {
                count += 1
            }
            .padding()
            .background(Color.blue)
            .foregroundColor(.white)
            .cornerRadius(10)
        }
        .padding()
    }
}

@main
struct MyApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}

Important Notes

SwiftUI uses a declarative style: you describe what the UI should be, not how to change it step-by-step.

It works well with live previews in Xcode, so you see changes instantly.

SwiftUI automatically adapts your app to different screen sizes and dark mode.

Summary

SwiftUI makes building user interfaces simple and fast.

It updates the UI automatically when data changes.

It works across all Apple devices with one codebase.