Sams Teach Yourself C in 21 Days

Decimal shift left by result

255 1 254

255 2 252

255 3 248

255 4 240

255 5 224

255 6 192

255 7 128

Decimal shift right by result

255 1 127

255 2 63

255 3 31

255 4 15

255 5 7

255 6 3

255 7 1

The Bitwise Logical Operators ....................................................................

Three bitwise logical operators are used to manipulate individual bits in an integer data

type, as shown in Table 20.1. These operators have names similar to the TRUE/FALSElogi-

cal operators you learned about in earlier chapters, but their operations differ.

TABLE20.1 The bitwise logical operators

Operator Action

& AND

| Inclusive OR

^ Exclusive OR

These are all binary operators, setting bits in the result to 1 or 0 depending on the bits in

the operands. They operate as follows:

• BitwiseANDsets a bit in the result to 1 only if the corresponding bits in both
  operands are 1 ; otherwise, the bit is set to 0. The ANDoperator is used to turn off, or
  clear, one or more bits in a value.


• Bitwise inclusive ORsets a bit in the result to 0 only if the corresponding bits in
  both operands are 0 ; otherwise, the bit is set to 1. The ORoperator is used to turn
  on, or set, one or more bits in a value.


• Bitwise exclusive ORsets a bit in the result to 1 if the corresponding bits in the
  operands are different (if one is 1 and the other is 0 ); otherwise, the bit is set to 0.
  The following are examples of how these operators work:

584 Day 20

OUTPUT

32 448201x-CH20 8/13/02 11:16 AM Page 584