lastindexof方法

向量類別的lastIndexOf()方法 (Vector Class lastIndexOf() method)

Syntax:

句法：

    public int lastIndexOf (Object ob);
public int lastIndexOf (Object ob, int indices);

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

  lastIndexOf()方法在java.util包中可用。

• lastIndexOf(Object ob) method is used to return the index of the last occurrence of the given element.

  lastIndexOf(Object ob)方法用于返回給定元素的最后一次出現的索引。

• lastIndexOf(Object ob, int indices) method is used to find the index of the last occurrence of the given object in this Vector and searching starts at the given indices.

  lastIndexOf(Object ob，int index)方法用于查找此Vector中給定對象最后一次出現的索引，并從給定索引開始搜索。

• These methods may throw an exception at the time of returning an index.

  這些方法在返回索引時可能會引發異常。

  IndexOutOfBoundsException: This exception may throw when the given parameter is not in a range.

  IndexOutOfBoundsException ：如果給定參數不在范圍內，則可能引發此異常。

• These are non-static methods and it is accessible with class objects and if we try to access these methods with the class name then we will get an error.

  這些是非靜態方法，可通過類對象訪問，如果嘗試使用類名訪問這些方法，則會收到錯誤消息。

Parameter(s):

參數：

• In the first case, lastIndexOf(Object ob)

  在第一種情況下， lastIndexOf(Object ob)

  • Object ob – represents the object for which the last occurrence element index to be returned.
  • 對象ob –代表要為其返回最后一個出現元素索引的對象。

• In the first case, lastIndexOf (Object ob, int indices)

  在第一種情況下， lastIndexOf(對象ob，int索引)

  • Object ob – represents the object for which the last occurrence element index to be returned.
  • 對象ob –代表要為其返回最后一個出現元素索引的對象。
  • int indices – represents the index of searching starts.
  • int index –表示搜索開始的索引。

Return value:

返回值：

In both the cases, the return type of the method is int - it gets the index of the last occurrence of the given object when exists otherwise it returns -1.

在這兩種情況下，方法的返回類型均為int-它在存在時獲取給定對象最后一次出現的索引，否則返回-1。

Example:

例：

// Java program to demonstrate the example 
// of lastIndexOf() method of Vector
import java.util.*;
public class LastIndexOfVector {
public static void main(String[] args) {
// Instantiates a vector object     
Vector < String > v = new Vector < String > (10);
// By using add() method is to add
// the elements in vector
v.add("C");
v.add("C++");
v.add("SFDC");
v.add("C++");
v.add("JAVA");
//Display Vector
System.out.println("v: " + v);
// By using lastIndexOf(object) method is used
// to return the index of last occurrence of the
// given object
System.out.println("v.lastIndexOf(C++): " + v.lastIndexOf("C++"));
// By using lastIndexOf(object, indices) method is used
// to return the index of last occurrence of the
// given object and searching starts from the 
// given indices
System.out.println("v.lastIndexOf(C++,4): " + v.lastIndexOf("C++", 4));
}
}

Output

輸出量

v: [C, C++, SFDC, C++, JAVA]
v.lastIndexOf(C++): 3
v.lastIndexOf(C++,4): 3

翻譯自: https://www.includehelp.com/java/vector-lastindexof-method-with-example.aspx

lastindexof方法