补充知识点

excersize/ch05.md

@@ -244,7 +244,7 @@ int main()
 {
 	unsigned aCnt = 0, eCnt = 0, iCnt = 0, oCnt = 0, uCnt = 0, spaceCnt = 0, tabCnt = 0, newLineCnt = 0;
 	char ch;
-	while (cin >> std::noskipws >> ch)
+	while (cin >> std::noskipws >> ch)  //noskipws(no skip whitespce)
 		switch (ch)
 	{
 		case 'a':
@@ -664,7 +664,7 @@ int main()
     while (cin >> read)
         if (read == tmp) break; else tmp = read;
 
-    if (cin.eof())  cout << "no word was repeated." << endl;
+    if (cin.eof())  cout << "no word was repeated." << endl; //eof(end of file)判断输入是否结束,或者文件结束符,等同于 CTRL+Z
     else            cout << read << " occurs twice in succession." << endl;
 
     return 0;