Android Question Use formula in string to calculate

[Pedro Caldeira]

Hello guys,
Is there any way to perform a calculation with the elements in a string

for instance, i have "2x10/20" it can be any other calculus, like "(234/403)-20*50" but they are string
can I somehow convert them to numbers to perform the operations ?

Thanks

 

[stevel05]

Have you seen this : https://www.b4x.com/android/forum/threads/b4x-eval-expressions-evaluator.54629/post-343073

 

[Mahares]

it can be any other calculus, like "(234/403)-20*50" but they are string
can I somehow convert them to numbers to perform the operations ?

You can use Smart String Literals. Here is an example:

Dim s As Double = $"${NumberFormat((234/403)-20*50, 1,4)}"$
Log(s)  'displays: -999.4194

 

[stevel05]

You can use Smart String Literals

The number passed needs to be a valid number, it won't work if you pass a string.

 

[Pedro Caldeira]

@stevel05 is right about the smart string, but the B4XClass works fine.
Thanks guys

 

[Mahares]

The number passed needs to be a valid number, it won't work if you pass a string.

Steve: Could you please give an example where it won't work. I am not sure I understand what you are saying. I was going by the examples that Pedro wrote
Thanks

 

[stevel05]

It's the calculation that is the problem. Pedro want's to be able to perform a calculation that is stored in a string which presumably is read from elsewhere. i.e.

Dim CalcStr as String = "(234/403)-20*50"
Dim s As Double = $"${NumberFormat(CalcStr, 1,4)}"$

Which will fail.