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Combine Basics

June 02, 2026 • 1 min read

Combine is Apple's reactive framework for handling streams of values over time (text input, timers, network results). SwiftUI uses it under the hood.

A publisher/subscriber

import Combine
class SearchModel: ObservableObject {
    @Published var query = ""
    @Published var results: [String] = []
    private var bag = Set<AnyCancellable>()
    init() {
        $query
            .debounce(for: .milliseconds(300), scheduler: RunLoop.main)
            .removeDuplicates()
            .sink { [weak self] q in self?.search(q) }
            .store(in: &bag)
    }
    func search(_ q: String) { /* ... */ }
}

debounce waits until the user stops typing — a classic search pattern.

Tip: For most new code, async/await covers your needs; reach for Combine when you need value streams and operators like debounce.

Summary

Combine models values that change over time. @Published is a Combine publisher; operators like debounce/removeDuplicates shape the stream.