What does compiler do internally when compile C# program?

@Rajkiran Swain
 

In case of C# , program compiles to IL code (Managed code) and at runtime it converted

into native machine code by JIT compile in CLR.

Nice question! Let me put it step by step.

 

Step1 :First of all, the compiler checks for syntax errors. If there's any syntax error, compiler warns the user.

 

Step2:If there's no syntax errors, all the comments, tabs and extra spaces from the program are removed.

 

Step3: The compiler recursively divides the whole program blockwise (e.g. if-else block, for loop, functions etc). Recursively because there maybe nested blocks.

 

Step4: All the blocks are further divided by semicolons.

 

Step5:Now the compiler has set of blockwise statements. The compiler converts all the statements written in C into Assembly Language.

 

Step6:While converting the statements from C to Assembly Language, the compiler will find the predefined functions from the header files you have imported using #include.

 

Step7: At last all the instructions in Assembly Language are merged into an .OBJ file.

 

Step8:When you run the program (by Ctrl+F9), the .OBJ file is further converted into .EXE file (Machine language) depending on the processor of your computer.