Java StringBuffer codePointAt()用法及代碼示例

StringBuffer類的codePointAt()方法按StringBuffer包含的順序在該索引處返回一個字符Unicode點。此方法返回該索引處字符的“Unicodenumber”。索引值必須介於0到length-1之間。
如果給定索引處的char值位於high-surrogate範圍內，則下一個索引小於此序列的長度，並且後續索引處的char值位於low-surrogate範圍內，則對應於此代理的補充代碼點對返回。否則，將返回給定索引處的char值。

用法:

public int codePointAt(int index)

參數：此方法采用一個參數索引，該參數索引是int值，表示要返回其unicode值的字符的索引。

返回值：此方法返回指定索引處字符的unicode號。

異常：當index為負或大於或等於length()時，此方法將引發IndexOutOfBoundsException。

下麵的程序演示StringBuffer類的codePointAt()方法：

示例1:

// Java program to demonstrate 
// the codePointAt() method 
  
class GFG { 
    public static void main(String[] args) 
    { 
  
        // create a StringBuffer object 
        StringBuffer str = new StringBuffer(); 
  
        // add the String to StringBuffer Object 
        str.append("Geeksforgeeks"); 
  
        // get unicode of char at position 10 
        int unicode = str.codePointAt(10); 
  
        // print the result 
        System.out.println("Unicode of Character "
                           + "at Position 10 "
                           + "in StringBuffer = "
                           + unicode); 
    } 
}

輸出：

Unicode of Character at Position 10 in StringBuffer = 101

示例2:演示IndexOutOfBoundsException

// Java program demonstrate 
// IndexOutOfBoundsException thrown by 
// the codePointAt() Method. 
  
class GFG { 
    public static void main(String[] args) 
    { 
        // create a StringBuffer object 
        // with a String pass as parameter 
        StringBuffer 
            str 
            = new StringBuffer("GeeksForGeeks Contribute"); 
  
        try { 
  
            // get char at position 25 which is 
            // greater then length 
            int i = str.codePointAt(25); 
        } 
  
        catch (IndexOutOfBoundsException e) { 
            System.out.println("Exception: " + e); 
        } 
    } 
}

輸出：

Exception: java.lang.StringIndexOutOfBoundsException: String index out of range: 25

參考文獻：
https://docs.oracle.com/javase/10/docs/api/java/lang/StringBuffer.html#codePointAt(int)

相關用法

注：本文由純淨天空篩選整理自AmanSingh2210大神的英文原創作品 StringBuffer codePointAt() method in Java with Examples。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。