Type switch
A type switch is a Go control-flow construct that selects a branch according to the dynamic type of an interface value.
Go in Practice, Second Edition
A type switch statement is a Go control-flow construct that selects a case according to the dynamic type of an interface value.
- How it is used
- Dispatches arbitrary interface values to type-specific operations inside generic functions.
- How deep it goes
- Explains syntax, conversions, parsing, unsupported types, named-type behavior, and the reflection-based kind-switch alternative.
- Examples
- Demonstrates a variadic mixed-value sum, string parsing, a named MyInt type, unsupported-type output, and a reflect-based kind switch.
- What you can do after
- Builds generic Go functions that process supported interface values and choose exact-type or underlying-kind dispatch.
Read how Go in Practice, Second Edition explains type switch →
Go in Action, Second Edition
A type switch is a Go control-flow construct that selects a case according to the dynamic type of an interface value.
- How it is used
- Handles type-specific behavior when an interface value may contain several concrete types.
- How deep it goes
- Compares interface dynamic types and contrasts multiple-case switches with single-type assertions, but does not detail runtime internals.
- Examples
- Uses Convertible values with MetricWeight, MetricVolume, ImperialWeight, and ImperialVolume cases to select a measurement system.
- What you can do after
- Apply it via Go’s type-switch syntax to route interface values into type-specific logic.
Read how Go in Action, Second Edition explains type switch →
Related concepts
- type assertionalternative to · A type assertion is a language construct that states or checks that a value has a specified type, with runtime behavior depending on the language.
- dynamic typinguses · Dynamic typing is a typing discipline in which type information and checks are determined primarily at runtime rather than fixed statically for variables.
- exceptionuses · An exception is a runtime signal or object representing an abnormal condition that interrupts ordinary program flow and may be handled or propagated.
- kind switchalternative to · A kind switch selects behavior based on the broad underlying category reported by Go reflection rather than on an exact named type.
- errors.Asalternative to · errors.As is a Go standard-library function that searches an error chain for a value assignable to a specified type and stores the result.
- case statementcontrasts with · A case or switch construct is a conditional control-flow construct that selects a branch or result from alternatives by matching a value or testing conditions.
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