Java HashMap replace() 方法

import java.util.HashMap;

public class Main {
  public static void main(String[] args) {
    HashMap capitalCities = new HashMap();

    capitalCities.put("England", "Cambridge");
    capitalCities.put("Germany", "Berlin");
    capitalCities.put("France", "Paris");
    capitalCities.put("USA", "Washington DC");
    
	// 替换键为 "England" 的条目的值为 "London"
    capitalCities.replace("England", "London");
	// 尝试替换不存在的键 "Canada" 的条目（不会进行任何替换）
    capitalCities.replace("Canada", "Ottawa");
	// 替换键为 "USA" 且旧值为 "Washington DC" 的条目的值为 "New York"
    capitalCities.replace("USA", "New York", "Washington DC");
    
	// 打印映射中的所有条目
    System.out.println(capitalCities);
  }
}

public V replace(K key, V newValue)
public boolean replace(K key, V oldValue, V newValue)