I wish to replace spaces with underscores in a sting

[n_techo]

Hello experts
maybe this is simple for you,

I have the following function.

void replacestring() {

quality = quality->Replace(" ", "_");

}

I wish to replace spaces with underscores in the string "quality"

When I compile I get the error message:

config_files.c: In function ‘replacestring’:
config_files.c:79: error: request for member ‘Replace’ in something not a structure or union

Here is the code,

config_files..c