Java BigInteger toString()用法及代码示例

BigInteger类为toString()提供2种方法。

• toString(int radix)：java.math.BigInteger.toString(int radix)方法以给定的基数返回此BigInteger的十进制String表示形式。基数参数决定应返回字符串的基数(二进制，八进制，十六进制等)。对于toString()，基数默认为10。如果基数在Character.MIN_RADIX到Character.MAX_RADIX(包括这两个字符)的范围之外，则默认为10。

  用法:

  public String toString(int radix)

  参数：此方法接受单个强制性参数基数，该基数是String表示形式的基数。

  
  

  返回值：此方法以给定的基数返回此BigInteger的十进制String表示形式。

  例子：

  Input: BigInteger1=321456 radix =2
  Output: 1001110011110110000
  Explanation: BigInteger1.toString(2)=1001110011110110000. 
  when radix is 2 then function will first convert the BigInteger 
  to binary form then it will return String representation of that binary number.
  
  Input: BigInteger1=321456 radix=16
  Output: 4e7b0
  Explanation: BigInteger1.toString()=4e7b0. 
  when radix is 16 then function will first convert the BigInteger 
  to hexadecimal form then it will return String representation of that hexadecimal number.
  

  以下示例程序旨在说明BigInteger类的toString(int radix)方法：

  示例1:当radix = 2时。表示二进制形式的字符串。

  // Java program to demonstrate 
  // toString(radix) method of BigInteger 
    
  import java.math.BigInteger; 
    
  public class GFG { 
    
      public static void main(String[] args) 
      { 
    
          // Creating BigInteger object 
          BigInteger b1; 
          b1 = new BigInteger("321456"); 
    
          // create radix 
          int radix = 2; 
    
          // apply toString(radix) method 
          String b1String = b1.toString(radix); 
    
          // print String 
          System.out.println("Binary String of BigInteger "
                             + b1 + " is equal to " + b1String); 
      } 
  }

  输出：

  Binary String of BigInteger 321456 is equal to 1001110011110110000
  

  示例2:当radix = 8表示八进制形式字符串

  // Java program to demonstrate  
  // toString(radix) method of BigInteger 
    
  import java.math.BigInteger; 
    
  public class GFG { 
    
      public static void main(String[] args) 
      { 
    
          // Creating BigInteger object 
          BigInteger b1; 
          b1 = new BigInteger("34567876543"); 
    
          // create radix 
          int radix = 8; 
    
          // apply toString(radix) method 
          String b1String = b1.toString(radix); 
    
          // print String 
          System.out.println("Octal String of BigInteger "
                            + b1 + " is equal to " + b1String); 
      } 
  }

  输出：

  Octal String of BigInteger 34567876543 is equal to 401431767677
  

  示例3:当radix = 16时表示十六进制十进制形式的字符串

  // Java program to demonstrate toString(radix) method of BigInteger 
    
  import java.math.BigInteger; 
    
  public class GFG { 
    
      public static void main(String[] args) 
      { 
    
          // Creating BigInteger object 
          BigInteger b1; 
          b1 = new BigInteger("8765432123456"); 
    
          // create radix 
          int radix = 16; 
    
          // apply toString(radix) method 
          String b1String = b1.toString(radix); 
    
          // print String 
          System.out.println("Hexadecimal String of BigInteger "
                             + b1 + " is equal to " + b1String); 
      } 
  }

  输出：

  Hexadecimal String of BigInteger 8765432123456 is equal to 7f8dc77d040
  



• toString()：java.math.BigInteger.toString()方法返回此BigInteger的十进制String表示形式。此方法对于将BigInteger转换为String很有用。在BigInteger上应用toString()之后，可以在BigInteger上应用所有字符串操作。

  用法:

  public String toString()

  返回值：此方法返回此BigInteger的十进制String表示形式。

  例子：

  Input: BigInteger1=321456 
  Output: 321456
  Explanation: BigInteger1.toString()=321456. 
  The answer is the String representation of BigInteger
  
  Input: BigInteger1=59185482345
  Output: 59185482345
  Explanation: BigInteger1.toString()=59185482345. 
  The answer is the String representation of BigInteger
  

  下面的程序说明BigInteger类的toString()方法：

  例：

  // Java program to demonstrate toString() method of BigInteger 
    
  import java.math.BigInteger; 
    
  public class GFG { 
    
      public static void main(String[] args) 
      { 
    
          // Creating 2 BigInteger objects 
          BigInteger b1, b2; 
          b1 = new BigInteger("35152194853456789"); 
    
          // apply toString() method 
          String b1String = b1.toString(); 
    
          // print String 
          System.out.println(b1String); 
    
          b2 = new BigInteger("7654323234565432345676543234567"); 
    
          // apply toString() method 
          String b2String = b2.toString(); 
    
          // print String 
          System.out.println(b2String); 
      } 
  }

  输出：

  35152194853456789
  7654323234565432345676543234567
  

参考： https://docs.oracle.com/javase/7/docs/api/java/math/BigInteger.html#toString(java.math.BigInteger)