MATLAB: Colon-generated arrays with or without brackets

arrayMATLAB

From what I can tell, the arrays a:d:b and [a:d:b] are exactly the same thing. For example,
    >> [1:3] == 1:3
    ans =
      1×3 logical array
       1   1   1
Yet, these two expressions give different results:
    >> [1:3]' + 1:3
    ans =
         2     3
    >> [1:3]' + [1:3]
    ans =
         2     3     4
         3     4     5
         4     5     6
Why?

Best Answer

The reason for this is the unexpected order in which this statement is evaluated:
[1:3]' + 1:3
([1:3]' + 1):3
([1;2;3]+1):3
[2;3;4]:3
2:3
[2,3]
Adding the brackets forces the grouping before and after the colon operator (parentheses would have worked as well).
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