珀尔 | Math::BigInt->digit() 方法

珀尔 | Math::BigInt->digit() 方法

Perl 中的Math::BigInt模块提供了表示具有任意精度和重载算术运算运算符的整数的对象。

Math::BigInt模块的digit()方法用于获取给定数字从右数的^{第 n}位。要从左侧获取数字，我们需要将n指定为负数。

Syntax: Math::BigInt->digit($n)

Parameter:
$n: An integer value denoting the digit to be extracted.

Returns: an integer value which represents the nth digit of the given number counting from the right side.

示例 1：使用Math::BigInt->digit()方法

#!/usr/bin/perl 
  
# Import Math::BigInt module
use Math::BigInt;
  
$num = 7821593604;
  
# Create a BigInt object
$x = Math::BigInt->new($num);
  
# Initialize n
$n = 4;
  
# Get the nth digit
# counting from right side 
$nth_digit = $x->digit($n);
  
print "${n}th digit in $num is $nth_digit.\n";
  
# Assign new value to n
$n = 6;
  
# Get the nth digit 
# counting from right side
$nth_digit = $x->digit($n);
  
print "${n}th digit in $num is $nth_digit.\n";

输出：

4th digit in 7821593604 is 9.
6th digit in 7821593604 is 1.

示例 2：使用Math::BigInt->digit()方法获取左起第 n 个数字

#!/usr/bin/perl 
  
# Import Math::BigInt module
use Math::BigInt;
  
$num = 7821593604;
  
# Create a BigInt object
$x = Math::BigInt->new($num);
  
# To get nth digit form 
# left side of the number
# we need to specify n 
# as a negative number 
  
# If n is negative then 
# then method will return
# nth digit from left side
# but counting will start from 1.
  
# Initialize n
$n = 4;
  
# Get the nth digit
# from left side 
$nth_digit = $x->digit(-$n);
  
print "${n}th digit from left in $num is $nth_digit.\n";
  
# Assign new value to n
$n = 6;
  
# Get the nth digit 
# counting from left side
$nth_digit = $x->digit(-$n);
  
print "${n}th digit from left in $num is $nth_digit.\n";

输出：

4th digit from left in 7821593604 is 1.
6th digit from left in 7821593604 is 9.

示例 3：使用Math::BigInt->digit()方法计算数字的位数之和

#!/usr/bin/perl 
  
# Import Math::BigInt module
use Math::BigInt;
  
$num = 7821593604;
  
# Create a BigInt object
$x = Math::BigInt->new($num);
  
# Get the length of the number
$length = $x->length();
  
# Variable to store sum
$sum = 0;
  
# for loop to calculate 
# sum of digits in given number
for($i = 0; $i < $length; $i++)
{
    # Get the ith digit from the
    # right side of the number 
    $sum = $sum + $x->digit($i);
  
}
  
# Print sum
print "Sum of digits in $num is $sum.";

输出：

Sum of digits in 7821593604 is 45.