How to create a string with names that differ, without a loop?

I want

D_N = {'K1'; 'K2'; '...' ;'K9' ; '...'};

until Kn is reached with n equal to a parameter of my program (for example 39).

I can chose to use:

for ii = 1:39
 D_N{ii} = sprintf('K%d', ii);
end

for ii = 1:39
 D_N{ii} = ['K' num2str(ii)];
end

But is there a way without using this stupid loop?

Answer 1

[Stephen23]

The fastest solution is to use the undocumented function sprintfc:

sprintfc('K%d',1:39)

As this is undocumented, use at your own risk. Otherwise arrayfun works, but feels like overkill:

arrayfun(@(n)sprintf('K%d',n),1:39,'uni',0)

As an alternative you could use the string data class and compose:

compose('K%d',1:39)

[Guillaume]

Since R2016b, there's absolutely no reason to use sprintfc and since it's undocumented, potentially disappearing in a future version, shouldn't be used at all.

compose doesn't require the use of the string class at all. compose produces a string array if the formatting string is of class string, and a cell array of char vectors if the formatting string is a char vector.

Always use compose or even easier the string composing functions as I've shown.

Answer 2

[Guillaume]

compose works exactly that way:

D_N = compose('K%d', 1:39)

Another option is to use string arrays:

D_N = "K" + (1:39)

which are easier to work with than cell arrays of char arrays.

In versions of matlab without string arrays or compose (pre-R2016b), you can use the completely undocumented sprintfc instead:

D_N = sprintfc('K%d', 1:39)