`mustBeUnderlyingType`

Checks that an array has the given underlying class.

Category: Programming > Functions

Syntax

mustBeUnderlyingType(A, typename)

Checks that the underlying class of A equals typename. Returns nothing if the check passes and throws an error if not.

Description

mustBeUnderlyingType is a validator: it inspects its input and either returns silently or raises an error with the identifier MATLAB:validators:mustBeUnderlyingType. The error message states the requirement that was violated, so the caller sees what was expected rather than a generic failure.

Unlike mustBeA, only the exact underlying class counts, and inheritance is not considered. For ordinary built-in arrays the underlying class is just class(A).

Input arguments

A: The value to check. Any array of the class the validator accepts.
typename: Class name as text. Several names may be given in a cell array.

Example

Passing and failing input

mustBeUnderlyingType(int8(1), 'int8');
disp('passed')
try
    mustBeUnderlyingType(int8(1), 'double')
catch err
    disp(err.message)
end

Output

passed
Value must have underlying type 'double'.

See also

mustBeA class isa mustBeNumeric