What is meant by protocol?

Always, execution of a C program starts from main() function.

• IDE is nothing but Integrated Development Environment. IDE is a tool that provides user interface with compilers to create, compile and execute C programs.
• Example: Turbo C++, Borland C++ and DevC++. These provide Integrated Development Environment with compiler for both C and C++ programming language.

• There are so many compilers available in market for Windows operating system and UNIX. We are listing some of them here for your reference.

  • AMPC
  • CCS C Compiler
  • ch
  • clang
  • Cygwin
  • Digital mars
  • GCC compiler
  • MikroC Compiler
  • Portable C Compiler, Power C, QuickC, Ritchie C Compiler, Small-C

Yes. C language instructions/commands/functions and everything used in C program are case sensitive.

• Data types in C language are defined as the data storage format that a variable can store a data to perform a specific operation.
• Data types are used to define a variable before to use in a program.
• Size of variable, constant and array are determined by data types.

• Integer data type allows a variable to store numeric values. The storage size of int data type is 2 or 4 or 8 byte. It varies depend upon the processor in the CPU.
• Character data type allows a variable to store only one character. Storage size of character data type is 1.
• Float data type allows a variable to store decimal values. Storage size of float data type is 4. This also varies depend upon the processor in the CP.
• Double data type is also same as float data type which allows up-to 10 digits after decimal.

sizeof() function is used to find the memory space allocated for each data type in C.