需要帮助来解释继承代码中的for语句

Question

Consider for(File file : files ) in the following code. I've never seen this syntax before. I understand from context and behavior that it'a a for loop based on the number of records...similar to (for x=0;x<length.foo;++x) . Beyond that though, I'm not sure. Is this shorthand for a for loop that I've not learned yet? Is this a loop specifically for objects? More importantly... how do I describe it when I want to google information about that particular syntax?

CLARIFICATION: a second question, I'm also curious how this method of recursive file listing stores the list of filenames in file . Is this an array? a collection? or...? I'd like to know how I need to read the resulting file.

public static void main(String... aArgs) throws FileNotFoundException
{
    File startingDirectory= new File("CGT");
    List<File> files = WorkingFileListing2.getFileListingNoSort(startingDirectory);
    for(File file : files )
    {
       System.out.println(file);  //print filenames
    }
}

Answer 1

It is the so-called "for each" loop .

I'm also curious how this method stores the list of filenames in file .

It doesn't. It iterates over the elements of files , assigning them in turn to file (one at a time!). If you run the code, each iteration of the loop will print one filename.

how do I describe it when I want to google information about that particular syntax?

Google "java for-each".

Answer 2

It looks to me like the equivalent of a 'foreach' in C#. Searching Google for 'Java foreach' got me this: Detail on Java For-Each loop

Answer 3

这称为foreach循环 ，当您不想从数组中删除对象时，仅用于对象。