-(NSString *)replaceStringWithReplaceStr:(NSString *)replaceStr  asterisk:(NSInteger)startLocation length:(NSInteger)length {
    for (NSInteger i = 0; i < length; i++) {
        NSRange range = NSMakeRange(startLocation, 1);
        replaceStr = [replaceStr stringByReplacingCharactersInRange:range withString:@"*"];
        startLocation ++;
    }
    return replaceStr;
}

-(NSString *)replaceStringWithReplaceStr:(NSString *)replaceStr  asterisk:(NSInteger)startLocation length:(NSInteger)length {
    for (NSInteger i = 0; i < length; i++) {
        NSRange range = NSMakeRange(startLocation, 1);
        replaceStr = [replaceStr stringByReplacingCharactersInRange:range withString:@"*"];
        startLocation ++;
    }
    return replaceStr;
}