Remarks

The class is called ExpressionBuilder. It has three properties:

private static readonly MethodInfo ContainsMethod = typeof(string).GetMethod("Contains", new[] { typeof(string) });
 private static readonly MethodInfo StartsWithMethod = typeof(string).GetMethod("StartsWith", new[] { typeof(string) });
 private static readonly MethodInfo EndsWithMethod = typeof(string).GetMethod("EndsWith", new[] { typeof(string) });

One public method GetExpression that returns the lambda expression, and three private methods:

• Expression GetExpression<T>
• BinaryExpression GetExpression<T>
• ConstantExpression GetConstant

All the methods are explained in details in the examples.