Validate that value is nonempty or issue error



mustBeNonempty(value) issues an error if value is empty. This function does not return a value.

mustBeNonempty accepts user-defined objects if the class of the object implements this method:


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Use mustBeNonempty to validate that the input is not empty.

Create a containers.Map.

A = containers.Map;

Validate that A is not an empty value.

Error using mustBeNonempty (line 13)
Values must not be empty.

Creating a containers.Map with no input arguments results in an empty object.

This class restricts the value of Prop1 to nonempty values. The default value must also be nonempty.

classdef MyClass
      Prop1 {mustBeNonempty} = containers.Map(1,'First')

Create an object and assign a value to its property.

obj = MyClass;
obj.Prop1 = containers.Map;
Error setting 'Prop1' property of 'MyClass' class:
Values must not be empty.

When you assign a value to the property, MATLAB® calls mustBeNonempty with the value being assigned to the property. mustBeNonempty issues an error because the value assigned to Prop1 is empty.

This function restricts the input argument to be a nonempty character vector.

function str = mbNonempty(name)
        name (1,:) char  {mustBeNonempty}
    str = sprintf('Name: %s',name);

Calling this function with an empty character vector results in an error being thrown by mustBeNonempty.

Error using mbNonempty
Invalid input argument at position 1. Value must not be empty.

Input Arguments

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Value to validate, specified as a scalar or array of any one of the following:

  • Any MATLAB data type

  • MATLAB classes that implement isempty.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | logical | char | struct | table | cell | function_handle | categorical | datetime | duration | calendarDuration
Complex Number Support: Yes

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Introduced in R2017a