删掉字符串中最后一个字符

1.删掉字符串中最后一个字符

-(NSString *)descriptionWithLocale:(id)locale{
    NSMutableString *str = [NSMutableString string];
    [str appendString:@"(\n"];
    //遍历数组里的全部元素
    [self enumerateObjectsUsingBlock:^(id  _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
        [str appendFormat:@"\t%@,\n",obj];
    }];
    [str appendString:@")"];
    
    //查出最后一个','的范围
    NSRange range = [str rangeOfString:@"," options:NSBackwardsSearch];
    if (range.length != 0) {
        //删掉最后一个','
        [str deleteCharactersInRange:range];
    }
    return str;

}