第一步:创建一个HashMap并添加数据 我们首先需要一个HashMap并向其中添加一些键值对: importjava.util.HashMap;publicclassRemoveElementByValue{publicstaticvoidmain(String[]args){// 创建一个HashMap对象HashMap<String,Integer>map=newHashMap<>();// 添加键值对map.put("Apple",10);map.put("Banana",20)...
importjava.util.HashMap;importjava.util.Map;publicclassRemoveByValue{publicstaticvoidmain(String[]args){// 创建一个HashMapMap<String,Integer>map=newHashMap<>();// 向Map中添加元素map.put("Apple",1);map.put("Banana",2);map.put("Cherry",3);map.put("Date",2);// Date和Banana有相同的...
1、HashMap的remove方法实现 1 2 3 4 public V remove(Object key) { Entry<K,V> e = removeEntryForKey(key); return (e == null ? null : e.value); } 2、HashMap.KeySet的remove方法实现 1 2 3 public boolean remove(Object o) { return HashMap.this.removeEntryForKey(o) != null; }...
remove() 方法带有 key 和 value 两个参数:实例 import java.util.HashMap; class Main { public static void main(String[] args) { HashMap<Integer, String> sites = new HashMap<>(); sites.put(1, "Google"); sites.put(2, "Runoob"); sites.put(3, "Taobao"); System.out.println("HashMa...
Sites.remove(4); System.out.println(Sites); } } 5.删除所有键值对(key-value)可以使用 clear 方法: 复制代码 publicclassRunoobTest {publicstaticvoidmain(String[] args) {//创建 HashMap 对象 SitesHashMap<Integer, String> Sites =newHashMap<Integer, String>();//添加键值对Sites.put(1, "Google...
5.HashMap 的 remove() 方法执行原理. HashMap 中删除一个元素的过程,如下图所示: 根据对冲突的处理方式不同,哈希表有两种实现方式,一种开放地址方式(Open addressing),另一种是冲突链表方式(Separate chaining with linked lists)。JavaHashMap采用的是冲突链表方式。
hashmap.remove(Object key, Object value); Here,hashmapis anobjectof theHashMapclass. remove() Parameters Theremove()method takes two parameters. key- remove the mapping specified by thiskey value(optional) - removes the mapping only if the specifiedkeymaps to the specifiedvalue ...
util.HashMap; public class Main { public static void main(String[] args) { HashMap<String, String> capitalCities = new HashMap<String, String>(); capitalCities.put("England", "London"); capitalCities.put("Germany", "Berlin"); capitalCities.put("Norway", "Oslo"); capitalCities.put("...
the previous value associated withkey, ornullif there was no mapping forkey. (Anullreturn can also indicate that the map previously associatednullwithkey.) Implements Remove(Object, Object) Attributes RegisterAttribute Remarks Java documentation forjava.util.HashMap.remove(java.lang.Object). ...
value Object Returns Boolean the previous value associated withkey, ornullif there was no mapping forkey. (Anullreturn can also indicate that the map previously associatednullwithkey.) Implements Remove(Object, Object) Remarks Java documentation forjava.util.HashMap.remove(java.lang.Object). ...