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来源：互联网发布：开源电商 php 编辑：程序博客网时间：2024/06/08 13:44

4.25

学会了，如何从HashMap中提取key值和value的值。

Set keys = map.keySet( );if(keys != null) {Iterator iterator = keys.iterator( );while(iterator.hasNext( )) {Object key = iterator.next( );Object value = map.get(key);

或者是这样写也是可以的

Set entries = map.entrySet( );if(entries != null) {Iterator iterator = entries.iterator( );while(iterator.hasNext( )) {Map.Entry entry =iterator.next( );Object key = entry.getKey( );Object value = entry.getValue();;....}

最后的代码为：

public class Solution {    /**      *@param A : an integer array      *return : a integer       */    public int singleNumber(int[] A) {        // Write your code here        int size = A.length;        HashMap<Integer,Integer> map = new HashMap<Integer,Integer>();                int i = 0;        for(i = 0;i < size;i++){            if(map.containsKey(A[i])){                map.remove(A[i]);            }            else{                map.put(A[i],A[i]);            }        }        Set keys = map.keySet();    int x = 0 ;if(keys != null){Iterator iter = keys.iterator();while(iter.hasNext()){Object key = iter.next();x = (Integer)key;}}return x;            }}

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