Java ChoiceFormat format()用法及代碼示例

java.text.ChoiceFormat類的format()方法用於獲取附加限製字符串格式的字符串生成器，該格式值的特定限製值作為參數傳遞，該文本作為參數傳遞給該方法。

用法:

public StringBuffer format(double number,
                         StringBuffer toAppendTo,
                         FieldPosition status)

參數：此方法采用以下參數，如下所示

number:這是選擇格式對象的特定限製，必須為其找到格式並附加格式
toAppendTo:這是要附加格式的新文本
status:確定是否沒有特殊狀態要返回

返回值：此方法以StringBuffer對象的形式返回文本和格式的附加值。

異常：如果toAppendto值為null，則此方法引發NullPointerException。

下麵是說明format()方法的示例：

示例1:

// Java program to demonstrate 
// format() method 
  
import java.text.*; 
import java.util.*; 
import java.io.*; 
  
public class GFG { 
    public static void main(String[] argv) 
    { 
        try { 
  
            // creating and initializing ChoiceFormat 
            ChoiceFormat cf1 
                = new ChoiceFormat( 
                    "4#wed| 5#thu | 6#fri | 7#sat"); 
  
            // creating and initializing StringBuffer 
            StringBuffer str = new StringBuffer("Sun"); 
  
            // getting the required format with appended text 
            // ChoiceFormat Object 
            // using format() method 
            StringBuffer vlaue = cf1.format(6, str, null); 
  
            // display the result 
            System.out.print("Formated text with appended value: "
                             + vlaue.toString()); 
        } 
        catch (NullPointerException e) { 
            System.out.println("str is null"); 
            System.out.println("Exception thrown: " + e); 
        } 
    } 
}

輸出：

Formated text with appended value: Sunfri

示例2:

// Java program to demonstrate 
// format() method 
  
import java.text.*; 
import java.util.*; 
import java.io.*; 
  
public class GFG { 
    public static void main(String[] argv) 
    { 
        try { 
  
            // creating and initializing ChoiceFormat 
            ChoiceFormat cf1 
                = new ChoiceFormat( 
                    "4#wed| 5#thu | 6#fri | 7#sat"); 
  
            // creating and initializing StringBuffer 
            StringBuffer str = null; 
  
            // getting the required format with appended text 
            // ChoiceFormat Object 
            // using format() method 
            StringBuffer vlaue = cf1.format(6, str, null); 
  
            // display the result 
            System.out.print("Formated text with appended value: "
                             + vlaue.toString()); 
        } 
        catch (NullPointerException e) { 
            System.out.println("str is null"); 
            System.out.println("Exception thrown: " + e); 
        } 
    } 
}

輸出：

str is null
Exception thrown: java.lang.NullPointerException

參考： https://docs.oracle.com/javase/9/docs/api/java/text/ChoiceFormat.html#format-double-java.lang.StringBuffer-java.text.FieldPosition-

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注：本文由純淨天空篩選整理自RohitPrasad3大神的英文原創作品 ChoiceFormat format() 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。