遍历List和Map集合，遍历数组

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List集合

第一种方法：for-each(加强for循环)

package list;import java.util.ArrayList;import java.util.List;public class ListArray {public static void main(String[] args) {List<Object> listArray = new ArrayList<Object>();listArray.add("唐斐");listArray.add(521);listArray.add(new String("简兮"));for(Object data :listArray){System.out.println(data);}}}

第二种方法：迭代器

package list;import java.util.ArrayList;import java.util.Iterator;import java.util.List;public class ListArray {public static void main(String[] args) {List<Object> listArray = new ArrayList<Object>();listArray.add("唐斐");listArray.add(521);listArray.add(new String("简兮"));Iterator<Object> iterator = listArray.iterator();while(iterator.hasNext()){Object data = iterator.next();System.out.println(data);}}}

第三种方法：jsp/jstl <c:forEach></c:forEach>

<%@ page language="java" contentType="text/html; charset=UTF-8"  pageEncoding="UTF-8"%><%@ page import="java.util.List"%><%@ page import="java.util.ArrayList"%><%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%><%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>   <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><title>List遍历</title></head><body><%      List<String> name = new ArrayList<String>();      name.add("zhangSan");      name.add("liSi");      name.add("wangWu");      name.add("zhaoLiu");      pageContext.setAttribute("ns", name);  %>  <c:forEach var="item" items="${ns }">      <c:out value="name: ${item }"/><br/>  </c:forEach>  </body></html>

Map集合：

第一种方法：for-each(加强for循环)

package map;import java.util.HashMap;import java.util.Map;import java.util.Set;public class MapArray {public static void main(String[] args) {Map<Integer,String> hashMap = new HashMap<Integer,String>();hashMap.put(1, "丹");hashMap.put(2, "顶");hashMap.put(3, "鹤");Set<Integer> setKey = hashMap.keySet();for(Integer key : setKey){String value = hashMap.get(key);System.out.println(key+"~~~"+value);}}}

第二种方法：迭代器

package map;import java.util.HashMap;import java.util.Iterator;import java.util.Map;import java.util.Set;public class MapArray {public static void main(String[] args) {Map<Integer,String> hashMap = new HashMap<Integer,String>();hashMap.put(1, "丹");hashMap.put(2, "顶");hashMap.put(3, "鹤");Set<Integer> setKey = hashMap.keySet();Iterator<Integer> iterator = setKey.iterator();while(iterator.hasNext()){Integer key = iterator.next();String value = hashMap.get(key);System.out.println(key+"~~~"+value);}}}

第三种方法：泛型，类型Entry，for-each(加强for循环)

package map;import java.util.HashMap;import java.util.Map;import java.util.Map.Entry;import java.util.Set;public class MapArray {public static void main(String[] args) {Map<Integer,String> hashMap = new HashMap<Integer,String>();hashMap.put(1, "丹");hashMap.put(2, "顶");hashMap.put(3, "鹤");Set<Entry<Integer,String>> set = hashMap.entrySet();for(Entry<Integer,String> entry : set){Integer key = entry.getKey();String value = entry.getValue();System.out.println(key+"~~~"+value);}}}

第四种方法：泛型，类型Entry，迭代器

package map;import java.util.HashMap;import java.util.Iterator;import java.util.Map;import java.util.Map.Entry;import java.util.Set;public class MapArray {public static void main(String[] args) {Map<Integer,String> hashMap = new HashMap<Integer,String>();hashMap.put(1, "丹");hashMap.put(2, "顶");hashMap.put(3, "鹤");Set<Entry<Integer,String>> set = hashMap.entrySet();Iterator<Entry<Integer,String>> iterator = set.iterator();while(iterator.hasNext()){Entry<Integer,String> entry = iterator.next();Integer key = entry.getKey();String value = entry.getValue();System.out.println(key+"~~~"+value);}}}

第五种方法：jsp/jstl <c:forEach></c:forEach>

<%@ page language="java" contentType="text/html; charset=UTF-8"  pageEncoding="UTF-8"%><%@ page import="java.util.Map"%><%@ page import="java.util.LinkedHashMap"%><%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%><%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>   <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><title>Map遍历</title></head><body><%      Map<String,String> stu = new LinkedHashMap<String,String>();      stu.put("number", "001");      stu.put("name", "zhangSan");      stu.put("age", "23");      stu.put("sex", "male");      pageContext.setAttribute("stu", stu);  %>  <c:forEach var="item" items="${stu }">      <c:out value="${item.key }: ${item.value }"/><br/>  </c:forEach>  </body></html>

遍历数组：

第一种方法：普通for循环

package array;public class array {public static void main(String[] args) {Object [] array = new Object[]{1,"a",new String("d")};for(int i = 0;i<array.length;i++){System.out.println(array[i]);}}}

第二种方法：for-each

package array;public class array {public static void main(String[] args) {Object [] array = new Object[]{1,"a",new String("d")};for(Object data : array){System.out.println(data);}}}

第三种方法：jsp/jstl <c:forEach></c:forEach>

<%@ page language="java" contentType="text/html; charset=UTF-8"  pageEncoding="UTF-8"%><%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%><%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>   <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><title>数组遍历</title></head><body><%  String[] name = {"唐斐", "简兮", "安心", "柯洛"};  pageContext.setAttribute("ns", name);  %>  <c:forEach var="item" items="${ns}">      <c:out value="name: ${item}"/><br/>  </c:forEach> </body></html>

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