How to vertically concatenate two tables with different sizes

For example:

>> A = table(['A1';'A1';'A1'],[1;1;1],[1;1;1],...
'VariableNames',{'Var1' 'Var2' 'Var3'})

A = 

      Var1    Var2    Var3
      ____    ____    ____

      A1      1       1   
      A1      1       1   
      A1      1       1   

>> B = table(['B1';'B1'],[2;2],[2;2],...
'VariableNames',{'Var1' 'Var2' 'Var4'})

B = 

      Var1    Var2    Var4
      ____    ____    ____

      B1      2       2   
      B1      2       2

How can I vertically concatenate A and B like the following? Thanks!

    Var1    Var2    Var3    Var4
    ____    ____    ____    ____

    A1      1       1        NAN
    A1      1       1        NAN
    A1      1       1        NAN
    B1      2      NAN        2
    B1      2      NAN        2

[Mars]

Thank you, Walter! It works!

Answer 1

[Walter Roberson]

outerjoin(A,B,'MergeKeys', true)

It took me a few minutes to find the right command.

Answer 2

[Sterling Baird]

Also consider looking at FEX: tblvertcat which builds on outerjoin and supports 2+ tables and shared variable names

tblvertcat(A,B)

>>

    Var1    Var2    Var3    Var4
    ____    ____    ____    ____

     A1      1        1     NaN 
     A1      1        1     NaN 
     A1      1        1     NaN 
     B1      2      NaN       2 
     B1      2      NaN       2