Java中的堆栈set()方法与示例
Java Stack的set()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