优化foreach的使用

Question

我有一小段代码,每个代码都在使用.我已经优化了我的代码,但我的老板希望我进一步优化它.我不知道在这里可以做进一步的优化.

foreach (Match match in matches) {
    //When oveeride is false and you have to download all the files
    if (Override.Equals(false)) {
        //putting the matches from regular expression into DownloadFileStruct oject
        df = new DownloadFileStruct(match.Groups[1].Value, match.Groups[2].Value);

        //Adding DownloadFileStruct object to a array list
        DownloadFileList.Add(df);
    }

    //When override is true and a paticular file has to be downloaded
    else if (match.Groups[2].Value.Equals(OverrideFileName)) {
            //putting the matche from regular expression into a DownloadFileStruct oject
            df = new DownloadFileStruct(match.Groups[1].Value, match.Groups[2].Value);

            //Adding DownloadFileStruct object to a array list
            DownloadFileList.Add(df);
        }                   
    }               
}

我的老板说"你不需要'if'和'else if'在两个分支中执行相同的代码".

Answer 1

只需在if中使用OR,而不是重复两次代码.

它不是关于优化,它不需要维护2个完全相同的代码分支.

foreach (Match match in matches) {
    //When oveeride is false and you have to download all the files
    if (Override.Equals(false) || match.Groups[2].Value.Equals(OverrideFileName)) {
        //putting the matches from regular expression into DownloadFileStruct oject
        df = new DownloadFileStruct(match.Groups[1].Value, match.Groups[2].Value);

        //Adding DownloadFileStruct object to a array list
        DownloadFileList.Add(df);
    }                     
}

Answer 2

您可以将代码简化为:

foreach (Match match in matches)
{
    if (Override && !match.Groups[2].Value.Equals(OverrideFileName))
        continue;

    df = new DownloadFileStruct(match.Groups[1].Value, match.Groups[2].Value);
    DownloadFileList.Add(df);
}

或LINQ-ish:

DownloadFileList = 
    matches.Cast<Match>()
           .Where(x => !Override || x.Groups[2].Value.Equals(OverrideFileName))
           .Select(x => new DownloadFileStruct(x.Groups[1].Value,
                                               x.Groups[2].Value))
           .ToList();