Four Java methods for traversing Map
- 2021-06-28 12:28:21
- OfStack
Choose the best fit
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
/**
* Created by song on 2019/1/17.
**/
public class MapT {
public static void main(String[] args) {
Map<Integer,String> map=new HashMap<>();
map.put(1," No. 1 individual ");
map.put(2," No. 2 individual ");
map.put(3," No. 3 individual ");
map.put(4," No. 4 individual ");
// No. 1 Species: First available key Value of Then pass key Worth it value value
Set<Integer> set=map.keySet();// The generic here is key Worth Generic
for(Integer integer:set){
System.out.println(integer+"->"+map.get(integer));//key->value
}
// No. 2 species : adopt Map.values() Traverse all value But it cannot be traversed key
for(String s:map.values()){
System.out.println(s);
}
// No. 3 species : adopt Map.entrySet Using Iterators iterator ergodic key and value
Iterator<Map.Entry<Integer,String>> iterable=map.entrySet().iterator();
while(iterable.hasNext()){
Map.Entry<Integer,String>entry=iterable.next();
System.out.println(entry.getKey()+"->"+entry.getValue());
}
// No. 4 species : Direct Pass Map.entrySet ergodic key and value
// Most common
for(Map.Entry<Integer,String> entry:map.entrySet()){
System.out.println(entry.getKey()+"->"+entry.getValue());
}
// Note: Map.Entry Method Interpretation
//Map.Entry yes Map Declared 1 Internal interface, which is generic and defined as Entry<K,V> .It represents Map In 1 Entities ( 1 individual key-value Yes)
}
}
summary