从Java中的TreeMap中删除所有值
使用该clear()方法从TreeMap中删除所有值。
让我们首先创建一个TreeMap-
TreeMap<Integer,String> m = new TreeMap<Integer,String>();
向TreeMap添加一些元素-
m.put(1,"PHP"); m.put(2,"jQuery"); m.put(3,"JavaScript"); m.put(4,"Ruby"); m.put(5,"Java"); m.put(6,"AngularJS"); m.put(7,"ExpressJS");
现在让我们删除所有值-
m.clear();
以下是从TreeMap删除所有值的示例-
示例
import java.util.*;
public class Demo {
public static void main(String args[]) {
TreeMap<Integer,String> m = new TreeMap<Integer,String>();
m.put(1,"PHP");
m.put(2,"jQuery");
m.put(3,"JavaScript");
m.put(4,"Ruby");
m.put(5,"Java");
m.put(6,"AngularJS");
m.put(7,"ExpressJS");
System.out.println("TreeMap Elements...");
Collection res = m.values();
Iterator i = res.iterator();
while (i.hasNext()){
System.out.println(i.next());
}
System.out.println("TreeMap size = "+m.size());
m.clear();
System.out.println("\nTreeMap after removing all elements = "+m);
System.out.println("Size of TreeMap now = "+m.size());
}
}输出结果
TreeMap Elements...
PHP
jQuery
JavaScript
Ruby
Java
AngularJS
ExpressJS
TreeMap size = 7
TreeMap after removing all elements = {}
Size of TreeMap now = 0