Dev 일기장

Binary ↔ Decimal

자바

package temp;

import static org.hamcrest.CoreMatchers.is;
import static org.hamcrest.MatcherAssert.assertThat;

import org.junit.jupiter.api.Test;

public class ConvertDecimalAndBinaryTest {

  @Test
  public void testConvertDecimalToBinary() {
    int decimal = 21;
    String binary = Integer.toBinaryString(decimal);
    System.out.println(String.format("Decimal: %d -> Binary: %s", decimal, binary));
    assertThat(binary, is("10101"));
  }

  @Test
  public void testConvertBinaryToDecimal() {
    String binary = "1011010";
    int decimal = Integer.parseInt(binary, 2);
    System.out.println(String.format("Binary: %s -> Decimal: %s", binary, decimal));
    assertThat(decimal, is(90));
  }
}

• Binary To Decimal: Integer.toBinaryString(int n) 메소드 사용
• Decimal To Bianry: Integer.parseInt(String s, int radix) 메소드에 radix = 2를 넣고 사용 

파이썬은?

from unittest import TestCase


class TestConvertDecimalAndBinary(TestCase):
    def test_convert_decimal_to_binary(self):
        decimal = 74
        binary_including_0b = bin(decimal)
        binary_excluding_0b = bin(decimal)[2:]
        print(f"Decimal: {decimal} -> Binary(including 0b): {binary_including_0b}")
        print(f"Decimal: {decimal} -> Binary(excluding 0b): {binary_excluding_0b}")
        self.assertEqual(binary_including_0b, "0b1001010")
        self.assertEqual(binary_excluding_0b, "1001010")

    def test_convert_binary_to_decimal(self):
        binary = "10111110"
        decimal = int(binary, 2)
        print(f"Binary: {binary} -> Decimal: {decimal}")
        self.assertEqual(decimal, 190)

• Binary To Decimal: int(binary, 2)
• Decimal To Binary: bin(decimal)
  • "0b"를 빼고 싶을 때: bin(decimal)[2:]