hashmap put方法
HashMap類的put()方法 (HashMap Class put() method)
put() method is available in java.util package.
put()方法在java.util包中可用。
put() method is used to link the given value element with the given key element in this HashMap.
put()方法用于在此HashMap中鏈接給定值元素和給定鍵元素。
put() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.
put()方法是一個非靜態方法，只能通過類對象訪問，如果嘗試使用類名稱訪問該方法，則會收到錯誤消息。
put() method does not throw an exception at the time of replacing the old element if exists.
put()方法在替換舊元素(如果存在)時不會引發異常。
Syntax:
句法：
public Value put(Key key_ele, Value val_ele);
Parameter(s):
參數：
Key key_ele – represents the key element with which the given value element is to be linked.
Key key_ele –表示與給定值元素鏈接的鍵元素。
Value val_ele – represents the value element with which the given key element is to be linked.
值val_ele –表示將與給定鍵元素鏈接的value元素。
Return value:
返回值：
The return type of the method is Value, it returns the old element linked with the given key element when exists otherwise it returns null.
該方法的返回類型為Value ，如果存在則返回與給定鍵元素鏈接的舊元素，否則返回null。
Example:
例：
// Java program to demonstrate the example
// of Value put(Key key_ele, Value val_ele)
// method of HashMap
import java.util.*;
public class PutOfHashMap {
public static void main(String[] args) {
// Instantiates a HashMap object
Map < Integer, String > map = new HashMap < Integer, String > ();
// By using put() method is to add
// key-value pairs in a HashMap
map.put(10, "C");
map.put(20, "C++");
map.put(50, "JAVA");
map.put(40, "PHP");
map.put(30, "SFDC");
// Display HashMap
System.out.println("HashMap: " + map);
// By using put() method is to
// replace the existing value associated
// for the given key element with the
// new value element
map.put(50, "Microservices");
// Display Modified HashMap
System.out.print("HashMap: " + map);
}
}
Output
輸出量
HashMap: {50=JAVA, 20=C++, 40=PHP, 10=C, 30=SFDC}
HashMap: {50=Microservices, 20=C++, 40=PHP, 10=C, 30=SFDC}
翻譯自: https://www.includehelp.com/java/hashmap-put-method-with-example.aspx
hashmap put方法
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