dynamic if condition from string

Question

I am generating a expression from some business rules and it might look like this

0 > 1
12 < 14
"abc" != "xyz"
90 >= 12

Now I have to do certain implementations based on that condition. For example:

 string condition = "0 =1";
 if(condition)
 {
  // do something because condition is passed
 }
else
 { 
  // do something because condition is failed
 }

I have tried to do the same with the dynamic keyword but it is still not working. Any work around?

Edit : 1 modified code

string _initExp = "1";
string _validateCondition = "== 0";
string strcondition = _initExp + _validateCondition;
bool _condition = Convert.ToBoolean(strcondition); // Error statement

if (_condition)
{

}

For this your best bet would probably be using the recently release [`Roslyn C# compiler`](http://roslyn.codeplex.com/). That will allow you to parse and execute any piece of C# code as strings. — Erik Schierboom, May 22 '14 at 13:03
Read this: http://msdn.microsoft.com/en-us/library/86hw82a3(v=vs.110).aspx - as examples show you can't convert string `1 == 0` to `bool` value. — rosko, May 22 '14 at 13:30
@Zerotoinfinite Try this, http://social.msdn.microsoft.com/Forums/vstudio/en-US/e28e3e87-64c8-4c0e-b4a4-4513978bece5/how-to-execute-c-statment-in-a-string#81b2d976-1836-40cf-ae65-1dc158765210 — Bharadwaj, May 22 '14 at 13:35

sshashank124 · Accepted Answer · 2014-05-22T13:06:39.120

4

Why not just use bool:

bool condition = 0==1;
if(condition)
{
   // do something because condition is passed
}
else
{ 
   // do something because condition is failed
}

You can also simplify the following code:

bool condition = 0==1;
if(condition)
{
   return true;
}
else
{ 
   return false;
}

to:

bool condition = 0==1;
return condition;

Or for custom return values

bool condition = 0==1;
return condition ? "yes" : "no";

edited May 22 '14 at 13:06

answered May 22 '14 at 13:00

sshashank124

31,495
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2

`return condition;` would be sufficient. Why to check once again. – Bharadwaj May 22 '14 at 13:05
Or you could even use a lambda expression of some sorts. – Stijn Bernards May 22 '14 at 13:06
@Bharadwaj, Thank you. I wasn't able to express myself properly. I have updated my answer. Hope it is better. – sshashank124 May 22 '14 at 13:07
I am getting my condition in string format ex: "0 == 1" , when I am using below code to convert it to bool it is not working, probably because it is not able to parse this string as bool **bool _condition = Convert.ToBoolean(strcondition)** – Zerotoinfinity May 22 '14 at 13:09
@Zerotoinfinite, I think this will help: http://stackoverflow.com/questions/5029699/c-sharp-convert-string-expression-to-a-boolean-expression – sshashank124 May 22 '14 at 13:10
@Zerotoinfinite `strcondition` should be a `boolean value in string form`. – Bharadwaj May 22 '14 at 13:12
@Bharadwaj I have modified my question with new code. Can you assist me to convert that string into bool? – Zerotoinfinity May 22 '14 at 13:15
@Zerotoinfinite you can't. You need to change some logic for that. – rosko May 22 '14 at 13:34

dynamic if condition from string

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