The Function change_one_line()

The Function change_one_line()

change_one_line() receives three parameters: line, oldstr, and newstr. It will replace each occurrence of oldstr in line by newstr. This is the most complicated of the functions. Good that we isolated it. Modular top-down programming.

The pseudocode follows:

receives line, oldstr, and newstr as parameters

while oldstr occurs in line

replace oldstr by newstr

Note:     

• pos = line.find(old,pos+newstr.length());

don’t want to find oldstring again if oldstring is part of newstring e.g cause and because. Would create infinite loop.