C ++ primer plus Study Notes (1)

1. Function header (AS Interface)

The function header describes the interface between a function and the function header that calls it.

For example, main ():

The function header describes the interface between main () and the operating system.

Who is the return value (exit value) of int main?

A: Return to the operating system.

2. c ++ pre-processor

Like C ++, C ++ also uses a pre-processor that processes the source files before compilation.

For example: # include <iostream>

This compilation command causes the pre-processor to add the content of the iostream file to the Program (replacing the code line # include <iostream> in the program ).

3. Class Introduction

Class is a user-defined data structure.

Classes are for objects, just like types are for variables.

Class describes all the attributes of a data type. An object creates an object based on these descriptions.

4. The program can access the namespace STD method:

1. Using namespace STD; before function definition. (All functions in the file can be used)

2. Using namespace STD; put it in a specific function definition (this function can use STD ).

3. Use a Compilation instruction similar to Using STD: cout in a specific function.

4. Do not use the compilation command using. Use the prefix STD: for example, STD: cout <"yes" when you need to use the element of the namespace STD ".