将 Enumerator 对象中的当前项重置为第一项。
function moveFirst()
如果集合中没有项,则当前项将被设置为未定义。
示例在以下示例中,使用 moveFirst 方法从列表的开头对 Drives 集合的成员进行计算:
function ShowFirstAvailableDrive(){ var fso, s, e, x; //Declare variables. fso = new ActiveXObject("Scripting.FileSystemObject"); e = new Enumerator(fso.Drives); //Create Enumerator object. e.moveFirst(); //Move to first drive. s = ""; //Initialize s. do { x = e.item(); //Test for existence of drive. if (x.IsReady) //See if it's ready. { s = x.DriveLetter + ":"; //Assign 1<SUP>st</SUP> drive letter to s. break; } else if (e.atEnd()) //See if at the end of the collection. { s = "No drives are available"; break; } e.moveNext(); //Move to the next drive. } while (!e.atEnd()); //Do while not at collection end. return(s); //Return list of available drives. }要求
应用于:
参考
atEnd 方法item 方法 (JScript)
moveNext 方法