Prefix match in MATLAB

Question

Hey guys, I have a very simple problem in MATLAB:

I have some strings which are like this:

Pic001
Pic002
Pic003
004

Not every string starts with the prefix "Pic". So how can I cut off the part "pic" that only the numbers at the end shall remain to have an equal format for all my strings?

Greets, poeschlorn

Answer 1

If 'Pic' only ever occurs as a prefix in your strings and nowhere else within the strings then you could use STRREP to remove it like this:

>> x = {'Pic001'; 'Pic002'; 'Pic003'; '004'}

x = 

    'Pic001'
    'Pic002'
    'Pic003'
    '004'

>> x = strrep(x, 'Pic', '')

x = 

    '001'
    '002'
    '003'
    '004'

If 'Pic' can occur elsewhere in your strings and you only want to remove it when it occurs as a prefix then use STRNCMP to compare the first three characters of your strings:

>> x = {'Pic001'; 'Pic002'; 'Pic003'; '004'}

x = 

    'Pic001'
    'Pic002'
    'Pic003'
    '004'

>> for ii = find(strncmp(x, 'Pic', 3))'
x{ii}(1:3) = [];
end
>> x

x = 

    '001'
    '002'
    '003'
    '004'