Class Binary4

  • public class Binary4
extends Object
    A class that represents a binary (base-2) number. A binary number is made up of one or more binary digits called bits. A bit has a value that is equal to either 0 or 1. An 8-bit binary number is shown below.

    A Binary number owns the individual bits.

    To convert a binary number to its decimal (base-10) equivalent, each bit is multiplied by an increasing power of 2 starting from the right-most bit. For example, the decimal equivalent of the 8-bit binary number can be calculated as (1 * 128) + (0 * 64) + (0 * 32) + (1 * 16) + (0 * 8) + (1 * 4) + (1 * 2) + (1 * 1) = 151:

    The decimal equivalent of the 3-bit binary number can be calculated as (1 * 4) + (1 * 2) + (1 * 1) = 7:

    • Constructor Summary

      Constructors 
      Constructor Description
      Binary4​(Bit bit)
      Initializes this binary number to a single digit binary number by copying the specified bit.
      Binary4​(List<Bit> bits)
      Initializes this binary number to have the specified bits.

    • Constructor Detail

      • Binary4

        public Binary4​(Bit bit)
        Initializes this binary number to a single digit binary number by copying the specified bit.
        Parameters:
        bit - the bit to copy

      • Binary4

        public Binary4​(List<Bit> bits)
        Initializes this binary number to have the specified bits. The constructor copies the individual bits into this binary number.
        Parameters:
        bits - the bits of the binary number
        Throws:
        IllegalArgumentException - if bits.size() is less than 1

    • Method Detail

      • numberOfBits

        public int numberOfBits()
        Returns the number of bits in this binary number.
        Returns:
        the number of bits in this binary number

      • getBit

        public Bit getBit​(int index)
        Gets the bit at the given index. The returned bit cannot be used to modify this binary number.

        Index 0 is the index of the left-most bit.

        Parameters:
        index - the index of the bit to get
        Throws:
        IllegalArgumentException - if index is out of bounds for this binary number

      • setLeftmostBit

        public void setLeftmostBit​(Bit bit)
        Sets the leftmost bit by copying the value of bit into the leftmost bit.
        Parameters:
        bit - the value of the bit to set

      • toDecimal

        public int toDecimal()
        Returns the decimal (base 10) value of this binary number as an int value. If this binary number has 32 bits or more then the user of this method should expect that the result will be incorrect because of overflow.
        Returns:
        the decimal (base 10) value of this binary number

      • safeGetBits

        public List<Bit> safeGetBits()
        Returns a list of the bits of this binary number. The returned list cannot be used to modify the bits of this number.
        Returns:
        a list of bits equal to the list of bits of this number

      • shiftLeft

        public void shiftLeft​(int n)
        Shifts all of the bits of this binary number n positions to the left. The original n left-most bits are discarded (that is, those bits do not wrap around to the left). The n right-most bits are set to 0. For example, if this binary number is:

        1110101

        then shifting the bits of the number by 2 positions changes this binary number to:

        1010100

        Parameters:
        n - the number of positions to shift
        Throws:
        IllegalArgumentException - if n is less than zero
        IllegalArgumentException - if n is greater than the number of bits in this number

      • shiftLeft

        static void shiftLeft​(List<Bit> x)
        Using recursion, shifts the bits of the specified list one position to the left. The last bit of the specified list becomes equal to the binary digit 0. For example, if x is the list

        [1, 1, 0, 1]

        then shiftLeft(x) changes x to equal the list

        [1, 0, 1, 0]

        If x is empty then this method does nothing (and does not throw an exception).

        Parameters:
        x - a list of bits

      • toString

        public String toString()
        Returns a string representation of this binary number. The returned string is made up of the bit values (0 or 1) of the number from the left-most bit to the right-most bit.
        Overrides:
        toString in class Object
        Returns:
        a string representation of this binary number

      • getBits

        public List<Bit> getBits()
        Returns a reference to the list of bits; for testing purposes only.
        Returns:
        a reference to the list of bits of this binary number

      • main

        public static void main​(String[] args)
        A simple test method.
        Parameters:
        args - not used