“C” separates the syntax of the language from the I/O and other system level functions. This makes it easier to develop a compiler for a new platform.
Any data types other than characters and intrinsic integer and floating point types are separated from the core programming language. That was a major departure from any previous programming language. The pointer data type, which holds an address, was also a departure from High Order Languages. Instead of accessing a data variable directly by means of its mnemonic name, the variable could be accessed indirectly through its address stored in a pointer variable.
The function is the basic unit of program execution in that every program begins execution in a function named main and terminates when the main function ends. Later on, we will also use the term “method” as another name for “function”. Functions may call other functions, including themselves. Control flow within a function begins with the first statement in the function and ends with the last statement in the function. Each statement, however, may redirect control in accordance with the nature of the statement. When control reaches the end of the currently executing function, control returns to the calling function at the point immediately succeeding the function call. In this way, the path of execution can enter into an unlimited number of functions and at varied levels of nesting of function calls.
The Standard C Library is a collection of function libraries that every C compiler provides.
Likewise, the Standard C++ Library includes the Standard C Library and adds additional data types called classes.
In a given C++ program, the library functions and classes that are used may come from a variety of sources in addition to the Standard Libraries, such as: