10.7.3 Bits

Bit manipulation functions.

Note that for bitwise AND, OR, XOR of integer values etc you can use the java bitwise operators "&", "|", "^".

hasBit( value, bitIndex )

Determines whether a given integer has a certain bit set to 1.

• Parameters:
  • value (long integer): integer whose bits are to be tested
  • bitIndex (integer): index of bit to be tested in range 0..63, where 0 is the least significant bit
• Return value
  • (boolean): true if bit is set; more or less equivalent to (value & 1L<<bitIndex) != 0
• Examples:
  • hasBit(64, 6) = true
  • hasBit(63, 6) = false

bitCount( i )

Returns the number of set bits in the 64-bit two's complement representation of the integer argument.

• Parameters:
  • i (long integer): integer value
• Return value
  • (integer): number of "1" bits in the binary representation of i
• Examples:
  • bitCount(64) = 1
  • bitCount(3) = 2

toBinary( value )

Converts the integer argument to a binary string consisting only of 1s and 0s.

• Parameters:
  • value (long integer): integer value
• Return value
  • (String): binary representation of value
• Examples:
  • toBinary(42) = "101010"
  • toBinary(255^7) = "11111000"

fromBinary( binVal )

Converts a string representing a binary number to its integer value.

• Parameters:
  • binVal (String): binary representation of value
• Return value
  • (integer): integer value represented by binary string binVal
• Example:
  • fromBinary("101010") = 42