#1,175 – An Example of an Expression Tree

You can assign a lambda expression to an instance of an expression tree so that you then have the corresponding expression represented as a data structure.  Below is an example of how an expression is represented in an expression tree.

Suppose that we have the expression for converting Fahrenheit to Celsius, as:

We create an expression tree by decomposing the expression into a left side, operator and right side.  We then further decompose for any sub-expression that can be decomposed.  The resulting tree looks as follows:

We can interpret the expression tree as follows:

• Main expression: (f – 32) * 5 / 9
  • Left: (f – 32) * 5
    • Left: (f – 32)
      • Left: f
      • Operator: –
      • Right: 32
    • Operator: *
    • Right: 5
  • Operator: /
  • Right: 9