Rename the file in the NSDocumentDirectory in an iOS application

This post will show how to rename a file located in the NSDocumentDirectory in an iOS application

NOTE: If you are still not confident about loading and saving the file in NSDcoumentDirectory then see this How to Load/Save a file from/to the NSDocumentDirectory in an iOS device

Lets declare a method -(void)renameFile; to do the renaming work

-(void)renameFile{

        NSFileManager *fileManager = [NSFileManager defaultManager];

        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

        NSString *documentsDirectory = [paths objectAtIndex:0];

        NSString * oldPath =[[NSString alloc]init];

        NSString * newPath =[[NSString alloc]init];

        oldPath=[documentsDirectory stringByAppendingPathComponent:@"existing_file_name"];

        newPath=[documentsDirectory stringByAppendingPathComponent:@"new_file_name"];

        

        if ([fileManager fileExistsAtPath:oldPath]) {

            [fileManager moveItemAtPath:oldPath toPath:newPath error:nil];             

        }

}        

Here, oldPath is the path for your_file with existing file name and newPath is the path with new filename for the file that you want to rename. 
The main work is done by the method [ moveItemAtPath: toPath: error: ] which moves the file at oldPath to newPath

Suggestions and corrections are most welcome. If you have any, please do so without hesitation.