从Java中的HashMap检索所有键
假设以下是我们的HashMap-
HashMap<Integer, String>map = new HashMap<Integer, String>(); map.put(10, "A"); map.put(20, "B"); map.put(30, "C"); map.put(40, "D"); map.put(50, "E"); map.put(60, "F"); map.put(70, "G"); map.put(80, "H");
要检索所有键，请迭代每个键值对-
Set<Integer>set = map.keySet();
Iterator<Integer>i = set.iterator();
while (i.hasNext()) {
Integer res = i.next();
System.out.println(res + ": " + map.get(res));
}示例
import java.util.HashMap;
import java.util.Iterator;
import java.util.Set;
public class Demo {
public static void main(String[] args) {
HashMap<Integer, String>map = new HashMap<Integer, String>();
map.put(10, "A");
map.put(20, "B");
map.put(30, "C");
map.put(40, "D");
map.put(50, "E");
map.put(60, "F");
map.put(70, "G");
map.put(80, "H");
Set<Integer>set = map.keySet();
Iterator<Integer>i = set.iterator();
while (i.hasNext()) {
Integer res = i.next();
System.out.println(res + ": " + map.get(res));
}
}
}输出结果
80: H 50: E 20: B 70: G 40: D 10: A 60: F 30: C