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70 Saturday Morning

The item on the left side of the assignment operator must be some element that
can be assigned a value — that is, a variable, property or, in a Const statement,
a constant.
When assigning an object reference, the line must begin with the Set keyword.
The item on the right side of the assignment operator must be an expression —
anything that evaluates to a value.

The term expression means any VBA code that can be reduced, or evaluated,
to a single numerical or string value. Thus, 5+2-1 is an expression because
Note it can be evaluated to the single value 6. Likewise “Micro” & “soft” is an
expression because it evaluates to the single value “Microsoft.”
There are some restrictions regarding the data types of the two elements in an assign-
ment statement.
If you assign a string value to a numeric variable, any value other than True or False
to a Boolean variable, or any nonobject value to an object variable, an error occurs.
If you assign a value to a numeric variable that is out of the range for that type,
an error occurs.
If you assign a number value to a string variable, the number is converted to the
text equivalent.
If you assign a floating-point value to an integer variable, the value is rounded to
the nearest integer.

The = symbol is also used by VBA as a comparison operator, as explained later in this ses-
sion. It is always clear from the context whether this symbol is being used for assignment
or comparison.

The concept of an expression is important in programming. An expression
is anything that can be evaluated to a value. It can be a numeric value,
Note a string, an object reference, or a logical (True/False) value.

Numerical Operators
The numerical operators, sometimes called the mathematical operators, perform operations
with numbers. The familiar operations of addition, subtraction, multiplication, and division
are represented by the symbols +, -, *, and / respectively. There are three less commonly
used operations:

Integer division (\). Performs a division, and returns the integer part of the
answer; therefore, 11\3 evaluates to 3.
Exponentiation (^). Raises a number to a power. In VBA, 4^2 means “four to the
2
second power” or 4 , and evaluates to 16.
Modulus (mod). Performs a division and returns the remainder. For example, 18 mod
5 evaluates to 3. Floating-point numbers are rounded to integers when used with
mod.