Declaration, intialization,Assembler,High Level Language,Compiler,Linker,Loader,SDK,Source Program,Object Program,Algorithms ,identifiers, whitspaces,comments....
Declaration :
A declaration introduces a variables name such as var1 into a program and specifies its type such as int or float .
int var1;
also
float inches;
If a declaration also sets aside memory for the variable , it is also called a definition. The statement would be
int var1; // define a variable
var1= 10;
This is definition as well as declaration. however later on we will see that various kinds of declarations that are not definitions.
Initialization :
Variables can be initialized at the same time they are defined .For example
char charvar1 = 'A' ;
Assembler:
A program that translates or convert a program that is written in assemly language into an equivalent machine language is called an assembler.
High Level Languages:
Basic ,FORTRAN , COBOL, Pascal ,C , C++ ,C# and Java are high level languages.
Compiler:
A program that translates or convert instructions that are written in high level language into machine language.
A compiler cheks the source program for syntax error and if no error is found then converts the program into manchine language.
Source Program:
A program that is written in high level language is called source program.
Object Program:
The machine language version of the high level language program is called object program.
SDK:
The program that you write in high level language are developed using a software development kit (SDK).
Linker:
A program that combines the object program with other programs in the library and is used in the program to creat the executable code is called linker.
Loader:
A program that loads an executable program into main memory is called loader.
Algorithms:
A step by step problem solving process in which at finite time the result is found is called algorithms.
Identifiers:
Identifiers are names of things. A C++ identifier consists of letters,digits and underscore ( _ ). identifier must begin with a letter or underscore.
Whitespaces:
Every C++ program contain whitespaces. whitspaces include blanks , tabs and newline characters.They can be used to make program more readable.
Comments:
Comments symbols are // or / * ...*/. In a program compiler ignores the comments. comments are used for our convinence.