I need help with string formatting

Hello,

I need a formatted string and came up with this:

colFormatWidth = [ 5  25  10  10  10  10   5   5   5   5  10  ] ;
colFormatType  = {'d' 's' 'f' 'd' 'f' 'f' 'f' 'f' 'f' 'f' 'f' } ;
formatRowDummy = sprintf('%%%%%%d%s', colFormatType{:}  ) ;
formatRow      = sprintf(formatRowDummy, colFormatWidth) 

>> formatRow

formatRow =

%5d%25s%10f%10d%10f%10f%5f%5f%5f%5f%10f

Is there a smarter way to do this?

PS Additionally it will get even more messy if I try to achive something like

%10.4f

with this approach.

Answer 1

[Guillaume]

I don't know about smarter, this is actually quite smart. I would just add a comment on the formatRowDummy line to explain the treble escaping of the % character (it has to survive going through two sprintf).

If the format string becomes even more complex, then probably the best thing is to revert to a loop (either explicit for or arrayfun) building each subpart of the format, with a final concatenation. It might be slower but the code would be clearer.

As it is:

formatrows = arrayfun(...
    @(w, t) sprintf('%%%d%s', w, t{1}), ...
    colFormatWidth, colFormatType, 'UniformOutput', false);
formatrow = [formatrows{:}]