Introduction

• Build Tree, compile to Func -> pass it to the Where
• LINQ uses lambda expressions to build an expression tree, which it can then use to build a provider-specific query

Expression

• an instruction to do something
• a combination of operands (variables, literals, method calls) and operators that can be evaluated to a single value
• a set of stuff that produces a value
• smaller than function
• e.g x < 5

why we put the expression in the tree?

Complex expression can be easily evaluated using the expression tree

    Or

x>1    x< 10

delegate

• delete allows you to construct how the function works at run time
• we are pushing design-time to run-time