Used to compare expressions.
Syntax
result = expression1 comparisonoperator expression2
result = object1 Is object2
result = string Like pattern
Comparison operators have these parts:
| Part | Description |
|---|---|
| result | Required; any numeric variable. |
| expression | Required; any expression. |
| comparisonoperator | Required; any comparison operator. |
| object | Required; any object name. |
| string | Required; any string expression. |
| pattern | Required; any string expression or range of characters. |
Remarks
The following table contains a list of the comparison operators and the conditions that determine whether result is True, False, or Null.
| Operator | True if | False if | Null if |
|---|---|---|---|
< (Less than) |
expression1 < expression2 | expression1 >= expression2 | expression1 or expression2 = Null |
<= (Less than or equal to) |
expression1 <= expression2 | expression1 > expression2 | expression1 or expression2 = Null |
> (Greater than) |
expression1 > expression2 | expression1 <= expression2 | expression1 or expression2 = Null |
>= (Greater than or equal to) |
expression1 >= expression2 | expression1 < expression2 | expression1 or expression2 = Null |
= (Equal to) |
expression1 = expression2 | expression1 <> expression2 | expression1 or expression2 = Null |
<> (Not equal to) |
expression1 <> expression2 | expression1 = expression2 | expression1 or expression2 = Null |
The Is and Like operators have specific comparison functionality that differs from the operators in the table.
When comparing two expressions, you may not be able to easily determine whether the expressions are being compared as numbers or as strings. The following table shows how the expressions are compared or the result when either expression is not a Variant.
| If | Then |
|---|---|
| Both expressions are numeric data types (Byte, Boolean, Integer, Long, Single, Double, Date, Currency, or Decimal) | Perform a numeric comparison. |
| Both expressions are String | Perform a string comparison. |
| One expression is a numeric data type and the other is a Variant that is, or can be, a number | Perform a numeric comparison. |
| One expression is a numeric data type and the other is a string Variant that can't be converted to a number | A Type Mismatch error occurs. |
| One expression is a String and the other is any Variant except a Null | Perform a string comparison. |
| One expression is Empty and the other is a numeric data type | Perform a numeric comparison, using 0 as the Empty expression. |
| One expression is Empty and the other is a String | Perform a string comparison, using a zero-length string ("") as the Empty expression. |
If expression1 and expression2 are both Variant expressions, their underlying type determines how they are compared. The following table shows how the expressions are compared or the result from the comparison, depending on the underlying type of the Variant.
| If | Then |
|---|---|
| Both Variant expressions are numeric | Perform a numeric comparison. |
| Both Variant expressions are strings | Perform a string comparison. |
| One Variant expression is numeric and the other is a string | The numeric expression is less than the string expression. |
| One Variant expression is Empty and the other is numeric | Perform a numeric comparison, using 0 as the Empty expression. |
| One Variant expression is Empty and the other is a string | Perform a string comparison, using a zero-length string ("") as the Empty expression. |
| Both Variant expressions are Empty | The expressions are equal. |
When a Single is compared to a Double, the Double is rounded to the precision of the Single. If a Currency is compared with a Single or Double, the Single or Double is converted to a Currency.
Similarly, when a Decimal is compared with a Single or Double, the Single or Double is converted to a Decimal. For Currency, any fractional value less than .0001 may be lost; for Decimal, any fractional value less than 1E-28 may be lost, or an overflow error can occur. Such fractional value loss may cause two values to compare as equal when they are not.
Example
This example shows various uses of comparison operators, which you use to compare expressions.
Dim MyResult, Var1, Var2
MyResult = (45 < 35) ' Returns False.
MyResult = (45 = 45) ' Returns True.
MyResult = (4 <> 3) ' Returns True.
MyResult = ("5" > "4") ' Returns True.
Var1 = "5": Var2 = 4 ' Initialize variables.
MyResult = (Var1 > Var2) ' Returns True.
Var1 = 5: Var2 = Empty
MyResult = (Var1 > Var2) ' Returns True.
Var1 = 0: Var2 = Empty
MyResult = (Var1 = Var2) ' Returns True.