Solve the matematical equation in c#

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Dear Sir

i operate this 3(4*2) it shows syntax error and how can i check the user input expression is in correct format.
if i replace ( with '*(' then if i have equation like 3((482/100)*2) create problem please tell me if anyone have solution of it

Posted 8-Oct-13 22:34pm

rajbir singh thind

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3 solutions

Solution 4

Replace only a sequence of a digit following '(' with "*("
This way 3((482/100)*2) will become 3*((482/100)*2)
[instead of 3*(*(482/100)*2)]

Best, H

Posted 8-Oct-13 23:01pm

Herbisaurus

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rajbir singh thind 9-Oct-13 5:09am

but if i have(3((482/100)*2) then it becomes *3*((482/100)*2) then

Herbisaurus 9-Oct-13 9:28am

no, it doesn't, the most left '*' will not be inserted.
ONLY a sequence of a digit following a '(', and the only occurance in your string is "3(" will be replaced with "3*(" i.e. a '*' inserted in the middle of that digit and the '('.

if you need code for that let me know...

Solution 3

Before you parse the grammar, I suggest you to make it more regular, for instance making the multiplicative operator '*' mandatory.
Once you have a good grammar then you may find several options for building the actual parser (you may find ready-to-use one, use a tool, embed a script language in your application).

Posted 8-Oct-13 22:53pm

CPallini

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OriginalGriff · Accepted Answer · 2013-10-08T22:39:00

Depending on how you are evaluating your expressions - and you don't say so we have to guess - you will either need to rework your parser or actually implement your own. If you are relying on effectively compiling and running expressions in C# to solve this, then you are on a loser from teh start - you can't modify the compiler.

You could however take something like this: A Tiny Expression Evaluator[^] and tweak it to allow your (rather non-standard) input format.

Or just tell your users to add an operator...