Article
11/18/2011

ExpressionType Enumeration

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Describes the node types for the nodes of an expression tree.

Namespace: System.Linq.Expressions
Assembly: System.Core (in System.Core.dll)

Syntax

'Declaration
Public Enumeration ExpressionType

public enum ExpressionType

Members

	Member name	Description
	Add	An addition operation, such as a + b, without overflow checking, for numeric operands.
	AddChecked	An addition operation, such as (a + b), with overflow checking, for numeric operands.
	And	A bitwise or logical AND operation, such as (a & b) in C# and (a And b) in Visual Basic.
	AndAlso	A conditional AND operation that evaluates the second operand only if the first operand evaluates to true. It corresponds to (a && b) in C# and (a AndAlso b) in Visual Basic.
	ArrayLength	An operation that obtains the length of a one-dimensional array, such as array.Length.
	ArrayIndex	An indexing operation in a one-dimensional array, such as array[index] in C# or array(index) in Visual Basic.
	Call	A method call, such as in the obj.sampleMethod() expression.
	Coalesce	A node that represents a null coalescing operation, such as (a ?? b) in C# or If(a, b) in Visual Basic.
	Conditional	A conditional operation, such as a > b ? a : b in C# or If(a > b, a, b) in Visual Basic.
	Constant	A constant value.
	Convert	A cast or conversion operation, such as (SampleType)obj in C#or CType(obj, SampleType) in Visual Basic. For a numeric conversion, if the converted value is too large for the destination type, no exception is thrown.
	ConvertChecked	A cast or conversion operation, such as (SampleType)obj in C#or CType(obj, SampleType) in Visual Basic. For a numeric conversion, if the converted value does not fit the destination type, an exception is thrown.
	Divide	A division operation, such as (a / b), for numeric operands.
	Equal	A node that represents an equality comparison, such as (a == b) in C# or (a = b) in Visual Basic.
	ExclusiveOr	A bitwise or logical XOR operation, such as (a ^ b) in C# or (a Xor b) in Visual Basic.
	GreaterThan	A "greater than" comparison, such as (a > b).
	GreaterThanOrEqual	A "greater than or equal to" comparison, such as (a >= b).
	Invoke	An operation that invokes a delegate or lambda expression, such as sampleDelegate.Invoke().
	Lambda	A lambda expression, such as a => a + a in C# or Function(a) a + a in Visual Basic.
	LeftShift	A bitwise left-shift operation, such as (a << b).
	LessThan	A "less than" comparison, such as (a < b).
	LessThanOrEqual	A "less than or equal to" comparison, such as (a <= b).
	ListInit	An operation that creates a new IEnumerable object and initializes it from a list of elements, such as new List<SampleType>(){ a, b, c } in C# or Dim sampleList = { a, b, c } in Visual Basic.
	MemberAccess	An operation that reads from a field or property, such as obj.SampleProperty.
	MemberInit	An operation that creates a new object and initializes one or more of its members, such as new Point { X = 1, Y = 2 } in C# or New Point With {.X = 1, .Y = 2} in Visual Basic.
	Modulo	An arithmetic remainder operation, such as (a % b) in C# or (a Mod b) in Visual Basic.
	Multiply	A multiplication operation, such as (a * b), without overflow checking, for numeric operands.
	MultiplyChecked	An multiplication operation, such as (a * b), that has overflow checking, for numeric operands.
	Negate	An arithmetic negation operation, such as (-a). The object a should not be modified in place.
	UnaryPlus	A unary plus operation, such as (+a). The result of a predefined unary plus operation is the value of the operand, but user-defined implementations might have unusual results.
	NegateChecked	An arithmetic negation operation, such as (-a), that has overflow checking. The object a should not be modified in place.
	New	An operation that calls a constructor to create a new object, such as new SampleType().
	NewArrayInit	An operation that creates a new one-dimensional array and initializes it from a list of elements, such as new SampleType[]{a, b, c} in C# or New SampleType(){a, b, c} in Visual Basic.
	NewArrayBounds	An operation that creates a new array, in which the bounds for each dimension are specified, such as new SampleType[dim1, dim2] in C# or New SampleType(dim1, dim2) in Visual Basic.
	Not	A bitwise complement or logical negation operation. In C#, it is equivalent to (~a) for integral types and to (!a) for Boolean values. In Visual Basic, it is equivalent to (Not a). The object a should not be modified in place.
	NotEqual	An inequality comparison, such as (a != b) in C# or (a <> b) in Visual Basic.
	Or	A bitwise or logical OR operation, such as (a \| b) in C# or (a Or b) in Visual Basic.
	OrElse	A short-circuiting conditional OR operation, such as (a \|\| b) in C# or (a OrElse b) in Visual Basic.
	Parameter	A reference to a parameter or variable that is defined in the context of the expression. For more information, see ParameterExpression.
	Power	A mathematical operation that raises a number to a power, such as (a ^ b) in Visual Basic.
	Quote	An expression that has a constant value of type Expression. A Quote node can contain references to parameters that are defined in the context of the expression it represents.
	RightShift	A bitwise right-shift operation, such as (a >> b).
	Subtract	A subtraction operation, such as (a - b), without overflow checking, for numeric operands.
	SubtractChecked	An arithmetic subtraction operation, such as (a - b), that has overflow checking, for numeric operands.
	TypeAs	An explicit reference or boxing conversion in which nulla null reference (Nothing in Visual Basic) is supplied if the conversion fails, such as (obj as SampleType) in C# or TryCast(obj, SampleType) in Visual Basic.
	TypeIs	A type test, such as obj is SampleType in C# or TypeOf obj is SampleType in Visual Basic.
	Assign	An assignment operation, such as (a = b).
	Block	A block of expressions.
	DebugInfo	Debugging information.
	Decrement	A unary decrement operation, such as (a - 1) in C# and Visual Basic. The object a should not be modified in place.
	Dynamic	A dynamic operation.
	Default	A default value.
	Extension	An extension expression.
	Goto	A "go to" expression, such as goto Label in C# or GoTo Label in Visual Basic.
	Increment	A unary increment operation, such as (a + 1) in C# and Visual Basic. The object a should not be modified in place.
	Index	An index operation or an operation that accesses a property that takes arguments.
	Label	A label.
	RuntimeVariables	A list of run-time variables. For more information, see RuntimeVariablesExpression.
	Loop	A loop, such as for or while.
	Switch	A switch operation, such as switch in C# or Select Case in Visual Basic.
	Throw	An operation that throws an exception, such as throw new Exception().
	Try	A try-catch expression.
	Unbox	An unbox value type operation, such as unbox and unbox.any instructions in MSIL.
	AddAssign	An addition compound assignment operation, such as (a += b), without overflow checking, for numeric operands.
	AndAssign	A bitwise or logical AND compound assignment operation, such as (a &= b) in C#.
	DivideAssign	An division compound assignment operation, such as (a /= b), for numeric operands.
	ExclusiveOrAssign	A bitwise or logical XOR compound assignment operation, such as (a ^= b) in C#.
	LeftShiftAssign	A bitwise left-shift compound assignment, such as (a <<= b).
	ModuloAssign	An arithmetic remainder compound assignment operation, such as (a %= b) in C#.
	MultiplyAssign	A multiplication compound assignment operation, such as (a *= b), without overflow checking, for numeric operands.
	OrAssign	A bitwise or logical OR compound assignment, such as (a \|= b) in C#.
	PowerAssign	A compound assignment operation that raises a number to a power, such as (a ^= b) in Visual Basic.
	RightShiftAssign	A bitwise right-shift compound assignment operation, such as (a >>= b).
	SubtractAssign	A subtraction compound assignment operation, such as (a -= b), without overflow checking, for numeric operands.
	AddAssignChecked	An addition compound assignment operation, such as (a += b), with overflow checking, for numeric operands.
	MultiplyAssignChecked	A multiplication compound assignment operation, such as (a *= b), that has overflow checking, for numeric operands.
	SubtractAssignChecked	A subtraction compound assignment operation, such as (a -= b), that has overflow checking, for numeric operands.
	PreIncrementAssign	A unary prefix increment, such as (++a). The object a should be modified in place.
	PreDecrementAssign	A unary prefix decrement, such as (--a). The object a should be modified in place.
	PostIncrementAssign	A unary postfix increment, such as (a++). The object a should be modified in place.
	PostDecrementAssign	A unary postfix decrement, such as (a--). The object a should be modified in place.
	TypeEqual	An exact type test.
	OnesComplement	A ones complement operation, such as (~a) in C#.
	IsTrue	A true condition value.
	IsFalse	A false condition value.

Remarks

For more information about each enumeration value of this type, see the documentation on the CodePlex Web site.

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.