Java EnumMap clear()
Java EnumMap类的
clear()方法用于清除地图中的所有映射。此方法不会删除地图，而是会删除地图中的所有条目。
语法
参数
NA
返回
此方法不返回任何值。
异常
NA
示例1
import java.util.EnumMap;
public class EnumMapClearExample1 {
// create an enum
public enum Tutorial{
Java,Python,PHP,Android,AngularJS
};
public static void main(String[] args) {
EnumMap<Tutorial,String>map = new EnumMap<Tutorial,String >(Tutorial.class);
map.put(Tutorial.Java,"1");
map.put(Tutorial.Python,"2");
map.put(Tutorial.PHP,"3");
map.put(Tutorial.Android,"4");
map.put(Tutorial.AngularJS,"5");
System.out.println("Values in map before removing:\n"+map);
map.clear();
System.out.println("Values in map after removing:\n"+map);
}
}
输出:
Values in map before removing:
{Java=1, Python=2, PHP=3, Android=4, AngularJS=5}
Values in map after removing:
{}
示例2
import java.util.*;
public class EnumMapClearExample2 {
// create an enum
public enum Days {
Monday, Tuesday, Wednesday, Thursday
}
;
public static void main(String[] args) {
EnumMap<Days, String>map= new EnumMap<Days, String>(Days.class);
map.put(Days.Monday,"1");
map.put(Days.Tuesday,"2");
map.put(Days.Wednesday,"3");
map.put(Days.Thursday,"4");
System.out.println("Values in map before removing:\n"+map);
map.clear();
System.out.println("Values in map after removing:\n"+map);
}
}
输出:
Values in map before removing:
{
Monday=1, Tuesday=2, Wednesday=3, Thursday=4}
Values in map after removing:
{}
