交换向量元素的Java程序

Java.util.Collections类的swap()方法用于交换指定列表中指定位置的元素。如果指定的位置相等，则调用此方法会使列表保持不变。

句法：

public static void swap(List list, int i, int j)

参数：此方法将以下参数作为参数

• list –交换元素的列表。
• i -要交换的一个元素的索引。
• j -要交换的另一个元素的索引。

异常如果 i 或 j 超出范围 (i = list.size() || j = list.size())，则此方法抛出IndexOutOfBoundsException 。

示例 1：

Java

// Java program to Swap Elements of Java Vector
  
import java.util.Collections;
import java.util.Vector;
  
public class GFG {
    public static void main(String[] args)
    {
  
        // create vector
        Vector vector = new Vector();
  
        // insert elements in vector
        vector.add("A");
        vector.add("B");
        vector.add("C");
        vector.add("D");
        vector.add("E");
  
        // print original vector
        System.out.println("Before Swapping = "+vector);
  
        // call Collection.swap() method
        Collections.swap(vector, 0, 4);
  
        // print vector after swap two elements
        System.out.println("After Swapping = "+vector);
    }
}

输出

[A, B, C, D, E]
After swapping
[E, B, C, D, A]

示例 2：对于IndexOutOfBoundsException

Java

// Java program to demonstrate 
// swap() method for IndexOutOfBoundsException 
    
import java.util.*; 
    
public class GFG1 { 
    public static void main(String[] argv) throws Exception 
    { 
        try { 
    
            // creating object of List 
            List vector = new ArrayList(); 
    
            // populate the vector 
            vector.add("rohan"); 
            vector.add("manish"); 
            vector.add("simran"); 
            vector.add("ananya"); 
            vector.add("ishika"); 
    
            // pritning the vector before swap 
            System.out.println("Before swap: " + vector); 
    
            // swap the elements 
            System.out.println("\nTrying to swap elements"
                               + " more than upper bound index "); 
            Collections.swap(vector, 0, 5); 
    
            // priting the vector after swap 
            System.out.println("After swap: " + vector); 
        } 
    
        catch (IndexOutOfBoundsException e) { 
            System.out.println("Exception thrown : " + e); 
        } 
    } 
}

输出

Before swap: [rohan, manish, simran, ananya, ishika]

Trying to swap elements more than upper bound index 
Exception thrown : java.lang.IndexOutOfBoundsException: Index 5 out of bounds for length 5