📜  Java中的堆栈set()方法与示例

📅  最后修改于: 2022-05-13 01:55:14.285000             🧑  作者: Mango

Java中的堆栈set()方法与示例

Java Stackset()方法用于将使用 Stack 类创建的堆栈中的任何特定元素替换为另一个元素。这可以通过在 set() 方法的参数中指定要替换的元素的位置和新元素来完成。

句法:

public E set(int index, Object element)

参数:此函数接受两个参数,如上述语法所示,如下所述。

  • index :这是整数类型,指的是要从堆栈中替换的元素的位置。
  • element :它将替换现有元素的新元素,并且与堆栈具有相同的对象类型。

返回值:该方法从堆栈中返回被新值替换的前一个值。

异常:此方法抛出以下异常:

  • UnsupportedOperationException :如果此堆栈不支持设置操作
  • ClassCastException : 如果指定元素的类阻止它被添加到这个堆栈
  • NullPointerException : 如果指定元素为 null 并且此堆栈不允许 null 元素
  • IllegalArgumentException : 如果指定元素的某些属性阻止它被添加到此堆栈
  • IndexOutOfBoundsException : 如果索引超出范围 (index = size())

下面的程序说明了Java.util.Stack.set() 方法:

示例 1:

// Java code to illustrate set()
  
import java.io.*;
import java.util.*;
  
public class StackDemo {
    public static void main(String args[])
    {
        // Creating an empty Stack
        Stack stack
            = new Stack();
  
        // Use add() method to add elements in the stack
        stack.add("Geeks");
        stack.add("for");
        stack.add("Geeks");
        stack.add("10");
        stack.add("20");
  
        // Displaying the linkedstack
        System.out.println("Stack:"
                           + stack);
  
        // Using set() method to replace Geeks with GFG
        System.out.println("The Object that is replaced is: "
                           + stack.set(2, "GFG"));
  
        // Using set() method to replace 20 with 50
        System.out.println("The Object that is replaced is: "
                           + stack.set(4, "50"));
  
        // Displaying the modified linkedstack
        System.out.println("The new Stack is:"
                           + stack);
    }
}
输出:
Stack:[Geeks, for, Geeks, 10, 20]
The Object that is replaced is: Geeks
The Object that is replaced is: 20
The new Stack is:[Geeks, for, GFG, 10, 50]

示例 2:演示 IndexOutOfBoundException

// Java code to illustrate set()
  
import java.io.*;
import java.util.*;
  
public class StackDemo {
    public static void main(String args[])
    {
        // Creating an empty Stack
        Stack stack
            = new Stack();
  
        // Use add() method to add elements in the stack
        stack.add("Geeks");
        stack.add("for");
        stack.add("Geeks");
        stack.add("10");
        stack.add("20");
  
        // Displaying the linkedstack
        System.out.println("Stack:"
                           + stack);
  
        // Using set() method to replace 10th with GFG
        // and the 10th element does not exist
        System.out.println("Trying to replace 10th "
                           + "element with GFG");
  
        try {
            stack.set(10, "GFG");
        }
        catch (Exception e) {
            System.out.println(e);
        }
    }
}
输出:
Stack:[Geeks, for, Geeks, 10, 20]
Trying to replace 10th element with GFG
java.lang.ArrayIndexOutOfBoundsException: Array index out of range: 10