Return vector elements as a single integer

Question

In MATLAB, how can I return the contents of a vector as a single integer. For example, if a = [ 1 2 3 4 5 6 7 8 9 ], then I want a function that returns the num

Answer 1

You can use

result = a*10.^(numel(a)-1:-1:0).';

or equivalently

result = sum(a.*10.^(numel(a)-1:-1:0));

They seem to be about equally fast.

Answer 2

One approach assuming the input as a vector of one-digit numbers with str2num and num2str -

str2num(num2str(a,'%1d'))

Or

str2num(char(a+48)) %// Thanks to Luis!

Or

str2double(char(a+48))