//取出一個字符串中字母出現的次數。如:字符串:"abcde%^kka27qoq" ,輸出格式爲:a(2)b(1)k(2)... public class A { private static Scanner in; public static void main(String[] args) { System.out.println('a'-'A'); System.out.println("請輸入一個字符串:"); in = new Scanner(System.in); String line = in.nextLine(); Map<Character,Integer> map = new TreeMap<Character,Integer>(); for (int i = 0; i < line.length(); i++) { Character key = line.charAt(i); if(map.get(key)!=null){ int value = map.get(key)+1; map.put(key, value); } else map.put(key, 1); } Set<Character> set = map.keySet(); for (Character character : set) { System.out.print(character+"("+map.get(character)+")"); } System.out.println("\r\n......大寫轉小寫小寫轉大寫......"); StringBuilder sb = new StringBuilder(); for (int i = 0; i < line.length(); i++) { char c = line.charAt(i); if(c>=97&&c<132){ c = (char) (c-32); sb.append(c); } else if(c>=65&&c<=100){ c = (char) (c+32); sb.append(c); } else sb.append(c); } System.out.println(sb.toString()); } }
map集合小練習
發表評論
所有評論
還沒有人評論,想成為第一個評論的人麼? 請在上方評論欄輸入並且點擊發布.