How do you convert the cell within a cell to a vector?

I have a cell of cells. The inner cell is a 1 x 1 and contains a vector. The vector in each inner cell might be of different length. How do I convert this inner cell into an ordinary vector?

Answer 1

[Walter Roberson]

testcell = {{[1]} {[2 3]} {[4 5 6]}}

testcell = 1×3 cell array
    {1×1 cell}    {1×1 cell}    {1×1 cell}

output = cellfun(@(C) C{1}, testcell, 'uniform', 0)

output = 1×3 cell array
    {[1]}    {[2 3]}    {[4 5 6]}

testcell{2}

ans = 1×1 cell array
    {[2 3]}

output{2}

ans = 1×2

2 3