|Introduced in C# 3.0||Introduced in C# 4.0|
|Statically typed – This means the type of variable declared is decided by the compiler at compile time.||Dynamically typed - This means the type of variable declared is decided by the compiler at runtime time.|
|Need to initialize at the time of declaration.|
Looking at the value assigned to the variable
|No need to initialize at the time of declaration.|
|Errors are caught at compile time.|
Since the compiler knows about the type and the methods and properties of the type at the compile time itself
|Errors are caught at runtime|
Since the compiler comes to about the type and the methods and properties of the type at the run time.
|Visual Studio shows intellisense since the type of variable assigned is known to compiler.||Intellisense is not available since the type and its related methods and properties can be known at run time only|
will throw a compile error since the variable is not initialized. The compiler needs that this variable should be initialized so that it can infer a type from the value.
will compile and run
will compile and run since the compiler creates the type for obj1 as System.Int32 and then recreates the type as string when the value “I am a string” was assigned to it.
This code will work fine.