# Expression.Or Method

## Definition

Creates a BinaryExpression that represents a bitwise `OR`

operation.

## Overloads

Or(Expression, Expression) |
Creates a BinaryExpression that represents a bitwise |

Or(Expression, Expression, MethodInfo) |
Creates a BinaryExpression that represents a bitwise |

## Or(Expression, Expression)

Creates a BinaryExpression that represents a bitwise `OR`

operation.

```
public:
static System::Linq::Expressions::BinaryExpression ^ Or(System::Linq::Expressions::Expression ^ left, System::Linq::Expressions::Expression ^ right);
```

`public static System.Linq.Expressions.BinaryExpression Or (System.Linq.Expressions.Expression left, System.Linq.Expressions.Expression right);`

`static member Or : System.Linq.Expressions.Expression * System.Linq.Expressions.Expression -> System.Linq.Expressions.BinaryExpression`

`Public Shared Function Or (left As Expression, right As Expression) As BinaryExpression`

#### Parameters

- left
- Expression

An Expression to set the Left property equal to.

- right
- Expression

An Expression to set the Right property equal to.

#### Returns

A BinaryExpression that has the NodeType property equal to Or and the Left and Right properties set to the specified values.

#### Exceptions

`left`

or `right`

is `null`

.

The bitwise `OR`

operator is not defined for `left`

.Type and `right`

.Type.

### Examples

The following code example shows how to create an expression that represents a logical OR operation.

```
// Add the following directive to your file:
// using System.Linq.Expressions;
// This expression perfroms a logical OR operation
// on its two arguments. Both arguments must be of the same type,
// which can be boolean or integer.
Expression orExpr = Expression.Or(
Expression.Constant(true),
Expression.Constant(false)
);
// Print out the expression.
Console.WriteLine(orExpr.ToString());
// The following statement first creates an expression tree,
// then compiles it, and then executes it.
Console.WriteLine(Expression.Lambda<Func<bool>>(orExpr).Compile()());
// This code example produces the following output:
//
// (True Or False)
// True
```

```
' Add the following directive to your file:
' Imports System.Linq.Expressions
' This expression perfroms a logical OR operation
' on its two arguments. Both arguments must be of the same type,
' which can be Boolean or integer.
Dim orExpr As Expression = Expression.Or(
Expression.Constant(True),
Expression.Constant(False)
)
' Print the expression.
Console.WriteLine(orExpr.ToString())
' The following statement first creates an expression tree,
' then compiles it, and then executes it.
Console.WriteLine(Expression.Lambda(Of Func(Of Boolean))(orExpr).Compile()())
' This code example produces the following output:
'
' (True Or False)
' True
```

### Remarks

The resulting BinaryExpression has the Method property set to the implementing method. The Type property is set to the type of the node. If the node is lifted, the IsLifted and IsLiftedToNull properties are both `true`

. Otherwise, they are `false`

. The Conversion property is `null`

.

The following information describes the implementing method, the node type, and whether a node is lifted.

#### Implementing Method

The following rules determine the implementing method for the operation:

If the Type property of either

`left`

or`right`

represents a user-defined type that overloads the bitwise`OR`

operator, the MethodInfo that represents that method is the implementing method.Otherwise, if

`left`

.Type and`right`

.Type are integral or Boolean types, the implementing method is`null`

.

#### Node Type and Lifted versus Non-Lifted

If the implementing method is not `null`

:

If

`left`

.Type and`right`

.Type are assignable to the corresponding argument types of the implementing method, the node is not lifted. The type of the node is the return type of the implementing method.If the following two conditions are satisfied, the node is lifted and the type of the node is the nullable type that corresponds to the return type of the implementing method:

`left`

.Type and`right`

.Type are both value types of which at least one is nullable and the corresponding non-nullable types are equal to the corresponding argument types of the implementing method.The return type of the implementing method is a non-nullable value type.

If the implementing method is `null`

:

If

`left`

.Type and`right`

.Type are both non-nullable, the node is not lifted. The type of the node is the result type of the predefined bitwise`OR`

operator.If

`left`

.Type and`right`

.Type are both nullable, the node is lifted. The type of the node is the nullable type that corresponds to the result type of the predefined bitwise`OR`

operator.

## Or(Expression, Expression, MethodInfo)

Creates a BinaryExpression that represents a bitwise `OR`

operation.

```
public:
static System::Linq::Expressions::BinaryExpression ^ Or(System::Linq::Expressions::Expression ^ left, System::Linq::Expressions::Expression ^ right, System::Reflection::MethodInfo ^ method);
```

`public static System.Linq.Expressions.BinaryExpression Or (System.Linq.Expressions.Expression left, System.Linq.Expressions.Expression right, System.Reflection.MethodInfo method);`

`static member Or : System.Linq.Expressions.Expression * System.Linq.Expressions.Expression * System.Reflection.MethodInfo -> System.Linq.Expressions.BinaryExpression`

`Public Shared Function Or (left As Expression, right As Expression, method As MethodInfo) As BinaryExpression`

#### Parameters

- left
- Expression

An Expression to set the Left property equal to.

- right
- Expression

An Expression to set the Right property equal to.

- method
- MethodInfo

A MethodInfo to set the Method property equal to.

#### Returns

A BinaryExpression that has the NodeType property equal to Or and the Left, Right, and Method properties set to the specified values.

#### Exceptions

`left`

or `right`

is `null`

.

`method`

is not `null`

and the method it represents returns `void`

, is not `static`

(`Shared`

in Visual Basic), or does not take exactly two arguments.

`method`

is `null`

and the bitwise `OR`

operator is not defined for `left`

.Type and `right`

.Type.

### Remarks

The resulting BinaryExpression has the Method property set to the implementing method. The Type property is set to the type of the node. If the node is lifted, the IsLifted and IsLiftedToNull properties are both `true`

. Otherwise, they are `false`

. The Conversion property is `null`

.

The following information describes the implementing method, the node type, and whether a node is lifted.

#### Implementing Method

The following rules determine the implementing method for the operation:

If

`method`

is not`null`

and it represents a non-void,`static`

(`Shared`

in Visual Basic) method that takes two arguments, it is the implementing method.Otherwise, if the Type property of either

`left`

or`right`

represents a user-defined type that overloads the bitwise`OR`

operator, the MethodInfo that represents that method is the implementing method.Otherwise, if

`left`

.Type and`right`

.Type are integral or Boolean types, the implementing method is`null`

.

#### Node Type and Lifted versus Non-Lifted

If the implementing method is not `null`

:

If

`left`

.Type and`right`

.Type are assignable to the corresponding argument types of the implementing method, the node is not lifted. The type of the node is the return type of the implementing method.If the following two conditions are satisfied, the node is lifted and the type of the node is the nullable type that corresponds to the return type of the implementing method:

`left`

.Type and`right`

.Type are both value types of which at least one is nullable and the corresponding non-nullable types are equal to the corresponding argument types of the implementing method.The return type of the implementing method is a non-nullable value type.

If the implementing method is `null`

:

If

`left`

.Type and`right`

.Type are both non-nullable, the node is not lifted. The type of the node is the result type of the predefined bitwise`OR`

operator.If

`left`

.Type and`right`

.Type are both nullable, the node is lifted. The type of the node is the nullable type that corresponds to the result type of the predefined bitwise`OR`

operator.