[C++] Introduction to C++ Syntax & Variables

이 아이의 특징 .. 

1. native code 

2. machine language

3. machine dependent 

 

This code is written in machine (and assembly) language for a specific processor; thus it is non-portable or machine dependent. This is the native code for the 6502 processor. Machine language is both difficult to write and to understand. (That's why Woz added all of the comments on the right).

 

 

 

step 1 - text editor : vim 같은거 ! 처음에 텍스트 에디터로 코드 작성함 

step 2 - preprocessor : Performs text substitution on your source code / Converts processed source code to object code.

step 3 - compiler : converts processed source code to object code 

step 4 - linker : combines object files with library code to produce the executable image, 

step 5 - loader : reads the program on disk, loads any required shared libraries and starts the program running.

step 6 - CPU : responsible for executing your code 

 

그니까 1. 빔으로 텍스트 써서 코드 쓰면 2. 프리프로세서가 적은 텍스트를 코드로 substitute하고  3. 컴파일러가 sourcecode 를 object code 로 convert 해 4. 컴차일이 되면 링커가 뭔가 결과를 내기위해서 매치를 링크를 함 5. 로딩을 함 6. 결과를 냄 ???

 

 

/**
 *  @author Jimin
 *  @date Thu Aug 31
 *  @file h01.cpp
 */ -> (1) documentation comment
 
#include <iostream>
#include <string>
#include <iomanip> // -> (2) standard library

using namespace std; // -> (3) namespace directive

double convert(double temp); // -> (4) function prototype 

int main()
{
cout << "Enter a temperature in 화씨"; // -> (6) prompt
double fahr; // -> (7) variable statement 
cin >> fahr;
double celsius = convert(fahr); //-> (9) function call 
cout << "Converted: " << fanhr << "F -" << celsius << "C" << endl; // -> (10) output statement 
return 0; // -> (11) optional return 

double convert(double temp) // -> (14) parameter
{
return (temp -32 ) * 5.0 /9.0; // -> (13) expression
} 
// -> (12) function definition

 

1. Provides an initial value for a variable when it is created.

 - initialization

2. Associates a name with a type.

- declaration

3. Allocates memory for a new variable.

- definition

4. Types like the string type.

- library types

5. Places a value into an existing variable.

- assignment 

 

6. A set of bits interpreted according to a type.

- value