[ios] Swift 3 - Comparing Date objects

Date is Comparable & Equatable (as of Swift 3)

This answer complements @Ankit Thakur's answer.

Since Swift 3 the Date struct (based on the underlying NSDate class) adopts the Comparable and Equatable protocols.

  • Comparable requires that Date implement the operators: <, <=, >, >=.
  • Equatable requires that Date implement the == operator.
  • Equatable allows Date to use the default implementation of the != operator (which is the inverse of the Equatable == operator implementation).

The following sample code exercises these comparison operators and confirms which comparisons are true with print statements.

Comparison function

import Foundation

func describeComparison(date1: Date, date2: Date) -> String {

    var descriptionArray: [String] = []

    if date1 < date2 {
        descriptionArray.append("date1 < date2")
    }

    if date1 <= date2 {
        descriptionArray.append("date1 <= date2")
    }

    if date1 > date2 {
        descriptionArray.append("date1 > date2")
    }

    if date1 >= date2 {
        descriptionArray.append("date1 >= date2")
    }

    if date1 == date2 {
        descriptionArray.append("date1 == date2")
    }

    if date1 != date2 {
        descriptionArray.append("date1 != date2")
    }

    return descriptionArray.joined(separator: ",  ")
}

Sample Use

let now = Date()

describeComparison(date1: now, date2: now.addingTimeInterval(1))
// date1 < date2,  date1 <= date2,  date1 != date2

describeComparison(date1: now, date2: now.addingTimeInterval(-1))
// date1 > date2,  date1 >= date2,  date1 != date2

describeComparison(date1: now, date2: now)
// date1 <= date2,  date1 >= date2,  date1 == date2

Examples related to ios

Adding a UISegmentedControl to UITableView Crop image to specified size and picture location Undefined Symbols error when integrating Apptentive iOS SDK via Cocoapods Keep placeholder text in UITextField on input in IOS Accessing AppDelegate from framework? Autoresize View When SubViews are Added Warp \ bend effect on a UIView? Speech input for visually impaired users without the need to tap the screen make UITableViewCell selectable only while editing Xcode 12, building for iOS Simulator, but linking in object file built for iOS, for architecture arm64

Examples related to xcode

Undefined Symbols error when integrating Apptentive iOS SDK via Cocoapods Xcode 12, building for iOS Simulator, but linking in object file built for iOS, for architecture arm64 iPhone is not available. Please reconnect the device Make a VStack fill the width of the screen in SwiftUI error Failed to build iOS project. We ran "xcodebuild" command but it exited with error code 65 The iOS Simulator deployment targets is set to 7.0, but the range of supported deployment target version for this platform is 8.0 to 12.1 Xcode 10.2.1 Command PhaseScriptExecution failed with a nonzero exit code Git is not working after macOS Update (xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools) Xcode 10: A valid provisioning profile for this executable was not found Xcode 10, Command CodeSign failed with a nonzero exit code

Examples related to swift3

Xcode 9 Swift Language Version (SWIFT_VERSION) Convert NSDate to String in iOS Swift Waiting until the task finishes Type of expression is ambiguous without more context Swift Removing object from array in Swift 3 Generate your own Error code in swift 3 Swift 3: Display Image from URL add Shadow on UIView using swift 3 how to open an URL in Swift3 Correctly Parsing JSON in Swift 3

Examples related to beta

Swift 3 - Comparing Date objects How to localise a string inside the iOS info.plist file? Android Studio Gradle project "Unable to start the daemon process /initialization of VM"