Java中的 StringBuffer deleteCharAt() 方法及示例

Java.lang.StringBuffer.deleteCharAt() 是一种内置的Java方法，用于删除此序列中指定位置的字符。使序列减少 1 个字符。

句法：

public StringBuffer deleteCharAt(int indexpoint)

参数：该方法接受一个整数类型的参数索引点，它指的是要删除的字符的索引。
返回值：函数返回字符串或删除字符后返回此对象。
异常：如果索引点为负数或大于或等于 length()，则该方法抛出StringIndexOutOfBoundsException 。

例子：

Input : StringBuffer = worldofgeeks
        int indexpoint = 4
Output : worlofgeeks

下面的程序说明了 StringBuffer.deleteCharAt() 方法的工作：
方案一：

// Java program to demonstrate working
// of StringBuffer.deleteCharAt() method
  
import java.lang.*;
  
public class Geeks {
  
    public static void main(String[] args)
    {
  
        StringBuffer sbf = new StringBuffer("raghav");
        System.out.println("String buffer before deletion = " + sbf);
  
        // Deleting the character at indexpoint 5
        sbf.deleteCharAt(5);
        System.out.println("After deletion new StringBuffer = " + sbf);
    }
}

输出：

String buffer before deletion = raghav
After deletion new StringBuffer = ragha

方案二：

// Java program to demonstrate working
// of StringBuffer.deleteCharAt() method
  
import java.lang.*;
  
public class Geeks {
  
    public static void main(String[] args)
    {
  
        StringBuffer sbf = new StringBuffer("GeeksforGeeks");
        System.out.println("String buffer before deletion = " + sbf);
  
        // Deleting the character at indexpoint 5
        sbf.deleteCharAt(5);
        System.out.println("After deletion new StringBuffer = " + sbf);
    }
}

输出：

String buffer before deletion = GeeksforGeeks
After deletion new StringBuffer = GeeksorGeeks

方案 3：

// Java program to demonstrate working
// of StringBuffer.deleteCharAt() method
  
import java.lang.*;
  
public class Geeks {
  
    public static void main(String[] args)
    {
  
        StringBuffer sbf = new StringBuffer("Abhishek");
        System.out.println("String buffer before deletion = " + sbf);
  
        // Deleting the character at indexpoint -5
        sbf.deleteCharAt(-5);
        System.out.println("After deletion new StringBuffer = " + sbf);
    }
}

输出：

Exception in thread "main" java.lang.StringIndexOutOfBoundsException: 
                                             String index out of range: -5
    at java.lang.AbstractStringBuilder.deleteCharAt
                                          (AbstractStringBuilder.java:824)
    at java.lang.StringBuffer.deleteCharAt(StringBuffer.java:441)
    at Geeks.main(Geeks.java:14)