Monash University > School of Computer Science and Software Engineering > CSE1303 > Part B > Lectures > Lecture B02 notes

CSE1303 Computer Science
Semester 3 (summer), 2003
Part B
Lecture B02 notes: Binary and unsigned integers

In this lecture

• Place value systems
  • Base (radix)
  • Exponent
• Decimal (base 10)
• Binary (base 2)
• Powers of two
• Converting from binary
  • Assign each place a value (power of 2)
  • Add place values that contain 1, ignore place values that contain 0
• Converting to binary
  • Repeated division by 2, note remainders
  • Read result up page
• Hexadecimal ("hex") (base 16)
• Octal (base 8)
• Relationship between binary, hex and octal
  • Group 4 binary digits for hex
  • Group 3 binary digits for octal
• Using hex and octal in C programs
  • Leading 0 (digit-zero) for octal
  • Leading 0x (digit-zero letter-X) for hex
• Unsigned integers (n bits)
  • Smallest value: all zeroes (value 0)
  • Largest value: all ones (value 2ⁿ-1)
  • C unsigned integer types
    • unsigned char (8 bits)
    • unsigned short (usually 16 bits)
    • unsigned long (usually 32 bits)
    • unsigned long long (usually 64 bits)
    • unsigned int (usually 16 or 32 bits)

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Last modified 2002-12-04