Java StringBuffer deleteCharAt(int index)用法及代碼示例

Java StringBuffer 類的deleteCharAt(int index) 方法用於刪除該序列指定位置的字符。刪除一個字符後，當前序列縮短一個字符。

用法:

public StringBuffer deleteCharAt(int index)

參數：

數據類型	參數	描述
int	index	索引是要刪除的字符的位置。

返回值：

此 deleteCharAt(int index) 方法返回此對象。

異常：

StringIndexOutOfBoundsException - 如果索引為負或大於或等於字符串緩衝區的 length()。

兼容版本：

Java 1.2 及以上

例子1

public class StringBufferDeleteCharAtExample1 {
	public static void main(String[] args) {
		StringBuffer sb = new StringBuffer("javatpoint");
	    System.out.println("string1:" + sb);
	    // deleting the character at index 4
	    sb = sb.deleteCharAt(4);
	    System.out.println("After deleting:" + sb);
	   
	    sb = new StringBuffer("hello java");
	    System.out.println("string2:" + sb);
	    // deleting the character at index 5
	    sb = sb.deleteCharAt(5);
	    System.out.println("After deleting:" + sb);
	}
}

輸出：

string1:javatpoint
After deleting:javapoint
string2:hello java
After deleting:hellojava

例子2

此 deleteCharAt(int) 方法在提供負索引值時拋出異常。

public class StringBufferDeleteCharAtExample2 {
	public static void main(String[] args) {
		StringBuffer sb = new StringBuffer("javatpoint");
	    System.out.println("string1:" + sb);
	    // try to delete the character at index value negative
	    sb = sb.deleteCharAt(-1);
	    System.out.println("After deleting:" + sb);
	}
}

輸出：

Exception in thread "main" java.lang.StringIndexOutOfBoundsException:String index out of range:-1
	at java.lang.AbstractStringBuilder.deleteCharAt(Unknown Source)
	at java.lang.StringBuffer.deleteCharAt(Unknown Source)
	at StringBufferDeleteCharAtExample2.main(StringBufferDeleteCharAtExample2.java:6)
string1 = javatpoint

例子3

刪除 Character.charCount(thisSequence.codePointAt(index)) 方法的索引值處的字符。

public class StringBufferDeleteCharAtExample3 {
	public static void main(String[] args) {
		StringBuffer sb = new StringBuffer("javatpoint");
	    System.out.println("string:" + sb);
	    // deleting string buffer using character count at code point
	    int cp = sb.codePointAt(0);
	    System.out.println("codepoint at 0:"+cp);
	    int totalCharacter =Character.charCount(cp);
	    System.out.println("total character at codepoint "+cp+":" + totalCharacter);
	    sb = sb.deleteCharAt(totalCharacter);
	    System.out.println("after deleting at index "+totalCharacter +":"+ sb);
	}
}

輸出：

string:javatpoint
codepoint at 0:106
total character at codepoint 106:1
after deleting at index 1:jvatpoint

示例 4

在這個例子中，我們從用戶那裏獲取輸入字符串和字符索引。

import java.util.Scanner;

public class StringBufferDeleteCharAtExample4 {
	public static void main(String[] args) {
	    StringBuffer sb = new StringBuffer("");
	    
	    System.out.print("enter your string value:");
	    Scanner sc = new Scanner(System.in);
	    sb.append(sc.nextLine());
	    
	    System.out.print("enter index:");
        int index = sc.nextInt(); 
	   
        // deleting the character at input index
        System.out.println("after deleting resultant string:"+sb.deleteCharAt(index));
	    sc.close();
	}
}

輸出：

enter your string value:hello string
enter index:3
after deleting resultant string:helo string

相關用法

注：本文由純淨天空篩選整理自 Java StringBuffer deleteCharAt(int index) method。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。