10. Data-Related Operators and Directives

• Operators and directives are not part of the Intel instruction set.

• They are only understood by the Assembler (in our case, Microsoft MASM.)

• Various assemblers have differing syntaxes for operators and directives...

  • ...There is no single-defined assembler standard.

• Useful MASM operators and directives:

  • The OFFSET operator returns the distance of a variable from the beginning of its enclosing segment.

  • The PTR operator lets you override a variable's default size.

  • The TYPE operator returns the size (in bytes) of each element in an array.

  • The LENGTHOF operator returns the number of elements in an array.

  • The SIZEOF operator returns the number of bytes used by an array initializer.