e129. performing bitwise operations with biginteger.txt

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A BigInteger object is immutable. For a mutable object that supports bitwise operations, see e363 Performing Bitwise Operations on a Bit Vector. 
    // Create via an array of bytes in twos-complement form.
    // The byte-ordering is big-endian which means the most significant bit is in element 0.
    
    // A negative value
    byte[] bytes = new byte[]{(byte)0xFF, 0x00, 0x00}; // -65536
    
    // A positive value
    bytes = new byte[]{0x1, 0x00, 0x00}; // 65536
    BigInteger bi = new BigInteger(bytes);
    
    // Get the value of a bit
    boolean b = bi.testBit(3);                  // 0
    b = bi.testBit(16);                         // 1
    
    // Set a bit
    bi = bi.setBit(3);
    
    // Clear a bit
    bi = bi.clearBit(3);
    
    // Flip a bit
    bi = bi.flipBit(3);
    
    // Shift the bits
    bi = bi.shiftLeft(3);
    bi = bi.shiftRight(1);
    
    // Other bitwise operations
    bi = bi.xor(bi);
    bi = bi.and(bi);
    bi = bi.not();
    bi = bi.or(bi);
    bi = bi.andNot(bi);
    
    // Retrieve the current bits in a byte array in twos-complement form.
    // The byte-ordering is big-endian which means the most significant bit is in element 0.
    bytes = bi.toByteArray();