Now click the 'Search Button' to open the search dialog and enter the item to search with in all the files in the selected folder.Example;
Enter the item, say "//--" the slash used in the c++ file to ignore the line ,and search. If the files contain the item entered, those files will be displayed as below.

The picture above shows the files contain the item searched for.

Now select each file by clicking on it.The selected file will be opened as below:

After opening the file, the 'Search and Replace' Button can be clicked to search the items in the selected file.

Each item so found can be replaced using the 'Replace ' dialog by entering the item.