Differences

This shows you the differences between two versions of the page.

--- cpp_lesson01 [2019/02/09 10:31]
+++ cpp_lesson01 [2019/02/09 10:31] (current)
@@ Line 1: / Line 1: @@
+===== Lesson 1: Hello World! =====
+==== Reading ====
+Before you begin, please read this article: [[http://www.cplusplus.com/doc/tutorial/program_structure/|Structure of a Program]]
+==== Writing the Program ====
+In the editor of your choice, please write the following code. **Note:** The bluefish editor version 2.02 allows for an automatic structuring of a c++ program.
+<code>
+// My first c++ program
+#include <iostream>
+using namespace std;
+int main ()
+{
+   cout << "Hello World!";
+   return 0;
+}
+</code>
+**Note:** It is important to either read character by caracter or set your punctuation level to all in your Orca preferences for your editor.
+==== Explanations ====
+  - The first line of the program is a comment. The program will stop reading the line when it encounters "%%//%%" (two slashes).
+  - We include input/output preprocessing.
+  - We declare standard global variables.
+  - We leave a blank line. This is not manditory but it is a convention for readability.
+  - We define the main function. This is where the program begins. **Note:** The word main is followed by a pair of brackets "()". These are rounded brackets. Americans call these parenthesies.
+  - We write a left-brace %%({%%). All functions are enclosed by braces.
+  - We print our message to the screen. Notice the two left pointing arrows (less than characters <<). These tell the program to insert the words "Hello World" into the standard output stream. **Note:** The statement ends with a semicolon (;). All statements end with a semicolon.
+  - We set a return code of zero (0) and exit the main function.
+  - We end the main function with a right-brace (}).
+==== Compiling the Program ====
+Although not absolutely necessary, save your program with the "cpp" extension. We assume, for this exercise, you have named your program
+<code>
+hello1.cpp
+</code>
+and that it is stored in your home folder.
+To compile "hello1.cpp", at a terminal or console prompt, type:
+<code>
+c++ hello1.cpp
+</code>
+If your prompt returns with no messages, your program has compiled successfully. Otherwise, you will need to correct your code and compile the program again.
+==== Run Your Program ====
+Your compiled program is in a file called
+<code>
+a.out
+</code>
+To run your program type:
+<code>
+./a.out
+</code>
+You may, of course, rename your program to something more meaningful than "a.out". It will also save your compiled program if you rename it; otherwise, the next compile you do will overwrite it.
+**Note:** The "./" tells the operating system you understand you are executing a program.
+==== Formatting Your Output ====
+If we want to write more information to the screen, we may also want to format it. We can edit the line which begins "cout <<" to read as follows:
+<code>
+cout << "Hello World" << endl;
+</code>
+This will put an end-of-line character in our output stream. Now our prompt will appear on a separate line from our message to the world.
+==== Assignment ====
+  - Write a new program which will display the following message on a line of its own:<code>
+I am a c++ program.
+</code>
+  - Read the article [[http://www.cplusplus.com/doc/tutorial/variables/|Variables, Data Types]]

Vinux Project Wiki

User Tools

Site Tools

Differences

Page Tools