实例代码:
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import java.util.HashMap; import java.util.Iterator; import java.util.Map; public class Test { public static void main(String[] args) { int a = 0 , b = 0 , c = 0 ; // 第一种:通过Map.keySet()遍历Map及将Map转化为二维数组 Map<String, String> map1 = new HashMap<String, String>(); map1.put( "012013012013" , "张三" ); map1.put( "012013012014" , "张四" ); String[][] group1 = new String[map1.size()][ 2 ]; System.out.println( "第一种:通过Map.keySet()遍历map1的key和value" ); for (String key : map1.keySet()) { System.out.println( "key = " + key + " and value = " + map1.get(key)); group1[a][ 0 ] = key; group1[a][ 1 ] = map1.get(key); a++; } System.out.println( "map1.size()为:" + map1.size() + ",a为:" + a + ",group1数组的长度为:" + group1.length); System.out.println( "----------------------------------------------------" ); for ( int n = 0 ; n < group1.length; n++) { System.out.println( "key = " + group1[n][ 0 ] + " and value = " + group1[n][ 1 ]); } // 第二种:通过Map.entrySet()使用iterator()遍历Map及将Map转化为二维数组 Map<String, String> map2 = new HashMap<String, String>(); map2.put( "112013012013" , "李三" ); map2.put( "112013012014" , "李四" ); System.out.println( "\n" + "第二种:通过Map.entrySet()使用iterator()遍历map2的key和value" ); Iterator<Map.Entry<String, String>> iterator = map2.entrySet().iterator(); String[][] group2 = new String[map2.size()][ 2 ]; while (iterator.hasNext()) { Map.Entry<String, String> entry = iterator.next(); System.out.println( "key = " + entry.getKey() + " and value = " + entry.getValue()); group2[b][ 0 ] = entry.getKey(); group2[b][ 1 ] = entry.getValue(); b++; } System.out.println( "map2.size()为:" + map2.size() + ",b为:" + b + ",group2数组的长度为:" + group2.length); System.out.println( "----------------------------------------------------" ); for ( int n = 0 ; n < group2.length; n++) { System.out.println( "key = " + group2[n][ 0 ] + " and value = " + group2[n][ 1 ]); } // 第三种:通过Map.entrySet()遍历遍历Map及将Map转化为二维数组 Map<String, String> map = new HashMap<String, String>(); map.putAll(map1); map.putAll(map2); String[][] group3 = new String[map.size()][ 2 ]; System.out.println( "\n" + "第三种:通过Map.entrySet()遍历map的key和value " ); for (Map.Entry<String, String> entry : map.entrySet()) { System.out.println( "key = " + entry.getKey() + " and value = " + entry.getValue()); group3[c][ 0 ] = entry.getKey(); group3[c][ 1 ] = entry.getValue(); c++; } System.out.println( "map.size()为:" + map.size() + ",c为:" + c + ",group3数组的长度为:" + group3.length); System.out.println( "----------------------------------------------------" ); for ( int n = 0 ; n < group3.length; n++) { System.out.println( "key = " + group3[n][ 0 ] + " and value = " + group3[n][ 1 ]); } } } |
输出结果为:
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第一种:通过Map.keySet()遍历map1的key和value key = 012013012013 and value = 张三 key = 012013012014 and value = 张四 map1.size()为: 2 ,a为: 2 ,group1数组的长度为: 2 ---------------------------------------------------- key = 012013012013 and value = 张三 key = 012013012014 and value = 张四 第二种:通过Map.entrySet()使用iterator()遍历map2的key和value key = 112013012014 and value = 李四 key = 112013012013 and value = 李三 map2.size()为: 2 ,b为: 2 ,group2数组的长度为: 2 ---------------------------------------------------- key = 112013012014 and value = 李四 key = 112013012013 and value = 李三 第三种:通过Map.entrySet()遍历map的key和value key = 112013012014 and value = 李四 key = 112013012013 and value = 李三 key = 012013012013 and value = 张三 key = 012013012014 and value = 张四 map.size()为: 4 ,c为: 4 ,group3数组的长度为: 4 ---------------------------------------------------- key = 112013012014 and value = 李四 key = 112013012013 and value = 李三 key = 012013012013 and value = 张三 key = 012013012014 and value = 张四 |
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原文链接:http://blog.csdn.net/caihuangshi/article/details/17552933