First step towards C/C++

First step to learn C/C++ language

Before starting to learn C++, first we must think, how to build communication with a computer? To do this, we need to speak a language which a computer understand. Immediately it comes to our mind that, English can be the language that we can use to build communication with a computer. However there are very common similarities between learning English language and learning C++ programming language.

Before we start learning English language, first we start learning alphabets, then we use these alphabets to form words, then we have combined meaningful words together to form a sentence and sentences are used to construct a paragraph.

Similar to this, learning C/C++ programming is easy and before we start writing a program, we first know about the various components that we have used to form a program. These components include, alphabets, number, and special symbols and used them to construct variables, constants, and keywords. Then we have combined all these together to form an instruction, which a machine can understand. Finally, we have put multiple instructions together to form a program.

The C++ Character Set

The C++ inherits the C language character set and in computer language a character denotes any alphabets, digit, or special symbol used to represent an information.

In the C/C++ language, information represented by upper and lower case alphabets represents two different information. This is the reason C and C++ both are case sensitive languages. In addition to the above list of character set C/C++ also use a white space and various escape sequences. A white space character is used to print a blank space on the screen.

Escape Sequences

Escape sequences are used to represent certain special characters within string literals and character literals. As C character set consists of escape sequence begins with a back slash (\) and it represents a single character. Any character can be represented as character constant using escape sequence. The following escape sequences are available

The Keywords

Keywords are reserved words by the compiler. All the C keywords have designed with a specific meaning and can not be used for any other purpose. There are only 32 keywords defines with C89 standard and further derived to C++98 standard.

As listed in the above table, all the reserved keywork are formed using lower-case characters. This is true with ANSI C, later on it becomes ISO C90 and few more keywords are added to this list with upper-case and underscore as prefix.

Keywords added by ISO C99

The purpose of this list is to keep the compatibility with already written code. Since this was an uncommon way for naming in C it is likely that most of the code written through the years does not contain these words.

Keywords added by ISO C11

This set of keywords might not work with all the avaibale C compiler. It is certain that it will support the 32 words from the ANSI standard and most of the time this is enough.

Keywords as Macro from standard library

Keywords with upper-case is not vey common. So there are few other keywords are declared as part of header files and used as macro of lower-case and keeps the code as clean.