package ee; import java.util.HashMap; import java.util.Iterator; public class Demo { public static void main(String[] args) { HashMap<Integer, Integer> count = new HashMap<Integer, Integer>(); count.put(1,11); count.put(2,22); count.put(3,33); //錯誤的 會拋出異常 ----ConcurrentModificationException /* for (Integer i : count.keySet()) { if(i == 2){ count.remove(i); } System.out.println(i); }*/ //正確的 it.remove(); // 這個可以實現 遍歷的過程中刪除某個元素 Iterator<Integer> it = count.keySet().iterator(); while(it.hasNext()) { Integer key = it.next(); if(key == 2){ it.remove(); // 這個可以實現 遍歷的過程中刪除某個元素 } if(key == 3){ count.put(key, 44); } } for (Integer value : count.values()) { System.out.println(value); } } }
參考文檔:
https://www.cnblogs.com/cherish010/p/9178085.html
https://blog.csdn.net/u011517841/article/details/82955498