# XCTPerformanceMeasurement A measurement from a single iteration of a performance test. ``` class XCTPerformanceMeasurement ``` ## Topics ### Initializing a Measurement [`init(identifier: String, displayName: String, doubleValue: Double, unitSymbol: String)`](/documentation/XCTest/XCTPerformanceMeasurement/init(identifier:displayName:doubleValue:unitSymbol:)) Initializes a performance measurement for a single iteration with the value and unit of measurement. [`convenience init(identifier: String, displayName: String, doubleValue: Double, unitSymbol: String, polarity: XCTPerformanceMeasurement.Polarity)`](/documentation/XCTest/XCTPerformanceMeasurement/init(identifier:displayName:doubleValue:unitSymbol:polarity:)) Initializes a performance measurement for a single iteration with the value, unit of measurement, and polarity. [`convenience init(identifier: String, displayName: String, value: Measurement)`](/documentation/XCTest/XCTPerformanceMeasurement/init(identifier:displayName:value:)) Initializes a performance measurement for a single iteration with the value. [`convenience init(identifier: String, displayName: String, value: Measurement, polarity: XCTPerformanceMeasurement.Polarity)`](/documentation/XCTest/XCTPerformanceMeasurement/init(identifier:displayName:value:polarity:)) Initializes a performance measurement for a single iteration with the value and polarity. ### Identifying Measurements [`var displayName: String`](/documentation/XCTest/XCTPerformanceMeasurement/displayName) A human-readable name for a measurement. [`var identifier: String`](/documentation/XCTest/XCTPerformanceMeasurement/identifier) A unique identifier for a measurement. ### Accessing Measured Values [`var doubleValue: Double`](/documentation/XCTest/XCTPerformanceMeasurement/doubleValue) The measured value. [`var unitSymbol: String`](/documentation/XCTest/XCTPerformanceMeasurement/unitSymbol) A string that represents the unit of measurement. [`var value: Measurement`](/documentation/XCTest/XCTPerformanceMeasurement/value) The measured value, including the unit of measure. [`var polarity: XCTPerformanceMeasurement.Polarity`](/documentation/XCTest/XCTPerformanceMeasurement/polarity-swift.property) A constant that states whether larger or smaller measurements, relative to a set baseline, indicate better performance. [`enum Polarity`](/documentation/XCTest/XCTPerformanceMeasurement/Polarity-swift.enum) Constants that state whether larger or smaller measurements, relative to a set baseline, indicate better performance. ## Relationships ### Conforms To [`Hashable`](/documentation/Swift/Hashable) [`CustomStringConvertible`](/documentation/Swift/CustomStringConvertible) [`CVarArg`](/documentation/Swift/CVarArg) [`NSObjectProtocol`](/documentation/ObjectiveC/NSObjectProtocol) [`Equatable`](/documentation/Swift/Equatable) [`CustomDebugStringConvertible`](/documentation/Swift/CustomDebugStringConvertible) ### Inherits From [`NSObject-swift.class`](/documentation/ObjectiveC/NSObject-swift.class) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)