How to replace characters between flags in MATLAB

Question

Suppose I have a char variable in Matlab like this:

x = 'hello my name $ is Sean $ Daley.';

I want to replace the first '$' with the symbol '&', and the second '$' with the symbol '#'.

Furthermore, if I have a more complicated char such that pairs of '$' repeat many times, I want to repeat the same pattern. So the following:

y = 'hello $ my $ name is $ Sean $ Daley $.$.';

would be transformed into:

'hello & my # name is & Sean # Daley &.#.'

I have tried coding this manually via for loops and while loops, but the code is just so ugly. Are there any simple functions that I can use?

Answer 1

Since you're dealing with single characters and non-nested pairs of flags, you can easily do this with a simple call to find and some indexed replacement:

y = 'hello $ my $ name is $ Sean $ Daley $.$.';
index = find(y == '$');
y(index(1:2:end)) = '&';
y(index(2:2:end)) = '#';

And the result:

y =

    'hello & my # name is & Sean # Daley &.#.'