Restrict type with Generics Constraints

Cuong Pham

Hi everyone,

I want to build a example about Generics Constraint with the question:
How will the complier catch a error when user input string type but reasonable with int, float, double, long type?
Can you help me this problem?

Many thanks.

6 Replies

Know the answer? Post it — somebody with the same question will find it here.

Cuong Pham13y ago
Thanks everyone very much....I solved this problem with IFormattable

Best wishes for u !
Vulpes13y ago
Just use the 'struct' generic constraint which will prevent string (a class) from being used at compile time but will permit int, float, double and long which are all structs.
Iftikar Hussain13y ago
please refer the below link to compare string

http://www.c-sharpcorner.com/uploadfile/yougerthen/using-icomparable-and-icomparer-to-compare-objects/

Regards,
Iftikar
Iftikar Hussain13y ago
can you share the compare class?
Cuong Pham13y ago
Thanks ur attention

It means that you can initialize a object with string type, the compile time will catch error.

ex: Create a class Compare two number and method int Compare(T a, Tb);
and then in Main method:
ObjectClass t = new ObjectClass(); ----> ok
ObjectClass t = new ObjectClass(); ----> ok
ObjectClass t = new ObjectClass(); ----> ok
ObjectClass t = new ObjectClass(); ----> ok

but:
ObjectClass t = new ObjectClass(); ---> error

It only supports int, float, long, double.
Iftikar Hussain13y ago
Hi,
I am not clear about your query. Can you please explain bit more?

Regards,
Iftikar