# C1.CalcEngine.ExpressionEngine.Expression ## Content

Expression Class

Base class that represents parsed expressions.

Expression

public class Expression : IExpression, IComparable<IExpression>

Public Class Expression
    Implements IExpression, IComparable(Of IExpression)

For example:

Expression expr = engine.Parse(strExpression);
object val = expr.Evaluate();

Name	Description
Expression(IExpressionEngine)	Initializes a new instance of the Expression class.
Expression(IExpressionEngine, Token)	Initializes a new instance of the Expression class.
Expression(IExpressionEngine, object)	Initializes a new instance of the Expression class.

Name	Description
Engine	Gets the IExpressionEngine that owns this IExpression.
Expressions	Gets the expressions used in this expression for evaluation.
Token	Gets a token of this expression.

Name	Description
CompareTo(IExpression)	Compares this instance with a specified IExpression object.
Evaluate()	Gets a result of expression.
GetBool(IExpression)	Casts the result of evaluating an IExpression to the Boolean type.
GetDateTime(IExpression)	Casts the result of evaluating an IExpression to the DateTime type.
GetDouble(IExpression)	Casts the result of evaluating an IExpression to the Double type.
GetString(IExpression)	Casts the result of evaluating an IExpression to the String type.
GetTimeSpan(IExpression)	Casts the result of evaluating an IExpression to the TimeSpan type.
IsNull(object)	Checks whether the specified value is null od DBNull.
Optimize()	Optimizes this expression.