treeset java

TreeSet類的add()方法 (TreeSet Class add() method)

• add() method is available in java.util package.

  add()方法在java.util包中可用。

• add() method is used to add the given object(ob) to this TreeSet when it does not already exist otherwise it ignores it.

  add()方法用于將給定對象(ob)添加到此TreeSet中，如果該對象尚不存在，否則它將忽略它。

• add() 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.

  add()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。

• add() method may throw an exception at the time of adding an object.

  add()方法在添加對象時可能會引發異常。

  ClassCastException: This exception may throw when the given parameter is incompatible.

  ClassCastException ：如果給定參數不兼容，則可能引發此異常。

Syntax:

句法：

    public boolean add(Object ob);

Parameter(s):

參數：

• Object ob – represents the object (ob) to be added in this TreeSet.

  對象ob –表示要在此TreeSet中添加的對象(ob)。

Return value:

返回值：

The return type of the method is boolean, it returns true when the given object (ob) is to be added successfully otherwise it returns false when the given object is already exists in this TreeSet.

該方法的返回類型為boolean ，當成功添加給定對象(ob)時，它返回true；否則，當此TreeSet中已經存在給定對象時，它返回false。

Example:

例：

// Java program to demonstrate the example 
// of boolean add(Object ob) method of TreeSet 
import java.util.*;
public class AddOfTreeSet {
public static void main(String[] args) {
// Instantiates a TreeSet object
TreeSet < String > tree_set = new TreeSet < String > ();
// By using add() method is to add
// the given object of this
// TreeSet if not exists
tree_set.add("C");
tree_set.add("C++");
tree_set.add("JAVA");
tree_set.add("PHP");
tree_set.add("SFDC");
// Display TreeMap 
System.out.println("TreeSet: " + tree_set);
}
}

Output

輸出量

TreeSet: [C, C++, JAVA, PHP, SFDC]

翻譯自: https://www.includehelp.com/java/treeset-add-method-with-example.aspx

treeset java