本文共 1939 字，大约阅读时间需要 6 分钟。
增强for循环：
package Day01;import java.util.ArrayList;import java.util.HashMap;import java.util.HashSet;import java.util.Iterator;import java.util.List;import java.util.Map;import java.util.Map.Entry;import java.util.Set;import org.junit.Test;//文件复制public class Demo1 { // @Test public void main1() { int[] is = {1,2,3,4,5,6}; for (int i = 0;i < is.length; i++) { System.out.println(is[i]); } } //遍历内容使用 @Test public void test1() { int[] is = {1,2,3,4,5}; for(int value : is){ System.out.print(value+"\t"); } } //传统方式 @Test public void testSet() { Set set = new HashSet (); set.add(100); set.add(200); set.add(300); Iterator it = set.iterator(); while(it.hasNext()){ Integer key = it.next(); System.out.print(key+"\t"); } } @Test public void testlist() { List list = new ArrayList (); list.add("jack"); list.add("marry"); list.add("sisi"); for(String name : list){ System.out.print(name+"\t"); } } //传统方法 @Test public void testMap1(){ Map map = new HashMap (); map.put(100,"jack"); map.put(200,"marry"); map.put(300,"sisi"); Set set = map.keySet(); Iterator it = set.iterator(); while(it.hasNext()){ Integer key = it.next(); String value = map.get(key); System.out.println(key+"-"+value); } } @Test public void testMap2(){ Map map = new HashMap (); map.put(100,"jack"); map.put(200,"marry"); map.put(300,"sisi"); Set > set = map.entrySet(); Iterator > it = set.iterator(); while(it.hasNext()){ Entry entry = it.next(); Integer key = entry.getKey(); String value = entry.getValue(); System.out.println(key+"<->"+value); } }} 转载于:https://blog.51cto.com/357712148/2103586