Matlab：索引超出矩阵尺寸

Question

I am trying to run the following code:

classdef HelloWorld
    properties
        var;
        array;
    end

    methods
        function h = HelloWorld()
            h.var = 30;
            setArray(h);
            disp(h.array(10));
        end

        function setArray(h)
            for i=1:h.var
                h.array(i) = i*2;
            end
        end
    end
end

However, I get the following error:

Index exceeds matrix dimensions.

Error in HelloWorld (line 14)
        disp(h.array(10));

Answer 1

Because you're accessing an empty array.

What you need is a new copy of HelloWorld which have an initialized array.

classdef HelloWorld
    properties
        var;
        array;
    end

    methods
        function h = HelloWorld()
            h.var = 30;
            h=setArray(h);
            disp(h.array(10));
        end

        function h=setArray(h)
            for i=1:h.var
                h.array(i) = i*2;
            end
        end
    end
end