Pointer Arithmetic

Addition
- Integer Added to Pointer.
  - The integer is multiplied by the size of the object pointed to before adding to the address.
  - Interpret integer as number of objects between original address and new address.
  - Result is a pointer.
  - Interpret the result as a pointer to the object located a specified number of positions to the right, as in an array.
  - Examples:
    - Pointer to int: pi + 3 adds 12 to pi.
    - Pointer to double: pd + 3 adds 24 to pd.
Subtraction
- Between pointers and ints.
  - Same as addition, but subtracts.
  - Result is a pointer.
  - Interpret result as a pointer to the object located a specified number of positions to the left, as in an array.
- Between pointers.
  - Divides by the size of the object pointed to after subtracting addresses.
  - Result is an int.
  - Interpret result as number of objects in between two addresses.

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This page was last modified on Oct 20, 2000

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