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法律研究如何使用 Iterator 遍历 map 的键集？
首先，创建一个要进行迭代的 HashMap−
Map<String, String>map = new LinkedHashMap<>();
map.put("Jack","0");
map.put("Tim", "1");
map.put("David","2");
map.put("Tom", "3");
map.put("Kevin", "4");现在，使用 Iterator 映射到 keyset−
Iterator iterator = map.keySet().iterator();
迭代所有对 −
while (iterator.hasNext()) {
String resKey = (String) iterator.next();
System.out.println("Rank of " + resKey + " is " + map.get(resKey));
}示例
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
public class Demo {
public static void main(String[] args) {
Map<String, String>map = new LinkedHashMap<>();
map.put("Jack","0");
map.put("Tim", "1");
map.put("David","2");
map.put("Tom", "3");
map.put("Kevin", "4");
map.put("Jeff", "5");
map.put("Katie","6");
map.put("Steve", "7");
map.put("Andrew", "8");
map.put("Angelina", "9");
String str = (String) map.get("David");
System.out.println("Rank of David = " + str);
Iterator iterator = map.keySet().iterator();
while (iterator.hasNext()) {
String resKey = (String) iterator.next();
System.out.println("Rank of " + resKey + " is " + map.get(resKey));
}
}
}输出
Rank of David = 2 Rank of Jack is 0 Rank of Tim is 1 Rank of David is 2 Rank of Tom is 3 Rank of Kevin is 4 Rank of Jeff is 5 Rank of Katies is 6 Rank of Steve is 7 Rank of Andrew is 8 Rank of Angelina is 9
更新于: 2019-7-30
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