Throw an exception if an input variable name does not exist in the workspace.

str = input('Type a variable name: ','s');
if ~exist(str,'var')
    ME = MException('MyComponent:noSuchVariable', ...
        'Variable %s not found',str);
    throw(ME)
end

At the input prompt, enter any variable that does not exist in your workspace. For example, enter notaVariable.

Variable notaVariable not found

Since notVariable doesn't exist in your workspace, MATLAB creates an MException object, and then throws it.

Create a function, combineArrays, in your working folder.

function C = combineArrays(A,B)
try
    C = catAlongDim1(A,B);       % Line 3
catch exception
    throw(exception)             % Line 5
end
end

function V = catAlongDim1(V1,V2)
V = cat(1,V1,V2);                % Line 10
end

Call the combineArrays function with arrays of different sizes.

A = 1:5;
B = 1:4;

combineArrays(A,B)

Error using combineArrays (line 5)
Dimensions of matrices being concatenated are not consistent.

The stack refers to line 5 where MATLAB throws the exception.

Replace throw(exception) with rethrow(exception) on line 5 of the combineArrays function, and call the function again.

combineArrays(A,B)

Error using cat
Dimensions of matrices being concatenated are not consistent.

Error in combineArrays>catAlongDim1 (line 10)
V = cat(1,V1,V2);                % Line 10

Error in combineArrays (line 3)
    C = catAlongDim1(A,B);       % Line 3

The rethrow method maintains the original stack and indicates the error is on line 3.