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# AndAlso Operator

**Visual Studio .NET 2003**

Performs short-circuiting logical conjunction on two expressions.

result = expression1 AndAlso expression2

#### Parts

*result*- Required. Any
**Boolean**expression. The result is the**Boolean**result of comparison of the two expressions. *expression1*- Required. Any
**Boolean**expression. *expression2*- Required. Any
**Boolean**expression.

#### Remarks

A logical operation is said to be *short-circuiting* if the compiled code can bypass the evaluation of one expression depending on the result of another expression. If the result of the first expression evaluated determines the final result of the operation, there is no need to evaluate the other expression, because it cannot change the final result. Short-circuiting can improve performance if the bypassed expression is complex, or if it involves procedure calls.

If both *expression1* and *expression2* evaluate to **True**, *result* is **True**. If *expression1* evaluates to True and *expression2* evaluates to **False**, *result* is **False**. If *expression1* evaluates to **False**, *expression2* is not evaluated, and *result* is **False **(the operator is said to have short-circuited the expression). The following table illustrates how *result* is determined:

If expression1 is | And expression2 is | Value of result is |
---|---|---|

True | True | True |

True | False | False |

False | (not evaluated) | False |

#### Example

This example uses the **AndAlso** operator to perform a logical conjunction on two expressions. The result is a **Boolean** value that represents whether the entire conjoined expression is true. If the first expression is **False**, the second is not evaluated.

Dim A As Integer = 10 Dim B As Integer = 8 Dim C As Integer = 6 Dim myCheck As Boolean myCheck = A > B AndAlso B > C ' True. myCheck = B > A AndAlso B > C ' False. Second expression not evaluated. myCheck = A > B AndAlso C > B ' False. Second expression evaluated. Public Function FindValue(ByVal Arr() As Double, _ ByVal SearchValue As Double) As Double Dim I As Integer = 0 While I <= UBound(Arr) AndAlso Arr(I) <> SearchValue ' If I is greater than UBound(Arr), SearchValue is not checked. I += 1 End While If I >= UBound(Arr) Then I = –1 Return I End Function

#### See Also

Logical/Bitwise Operators | Operator Precedence in Visual Basic | Operators Listed by Functionality | And Operator | Logical Operators