Material Summary: Programming Languages and Your First Program

Programming languages bridge the gap between human-readable instructions and binary code computers understand. Like spoken languages have grammar rules, programming languages have syntax—strict rules defining how to structure valid code. C++ is one such language used for games and applications. You wrote your first C++ program using Outscal's online compiler: a "Hello World" program that displays text on screen. The code includes #include <iostream> for input/output capabilities, int main() as the program's entry point, and std::cout to output text. C++ is case-sensitive and requires precise punctuation—every statement ends with a semicolon. You experienced the programming feedback loop: write code, run it, see immediate results. By modifying the message text and running again, you saw how changes affect output. You also learned why syntax matters by intentionally breaking the code (removing a semicolon), which caused compilation errors. This demonstrated that even minor mistakes prevent programs from running, but error messages help identify and fix problems quickly.

You successfully wrote, executed, and modified a working C++ program, crossing from learning about programming to actually programming. You've seen code run and produce visible output on screen.

The program works, but what do components like #include, main(), and std::cout actually mean? Next, you'll understand each part's specific purpose and role in making the program function.

Recap

You learned that programming means writing precise, step-by-step instructions computers execute literally—but computers can't understand English. You need a way to communicate these instructions in a form computers can process.

Programming Languages: The Bridge Between You and the Computer

Computers don't speak English—they only understand binary (1s and 0s). Writing instructions directly in binary is nearly impossible for humans. Programming languages solve this problem by providing a middle ground: you write instructions in a language that's readable by humans, and special software translates it into binary the computer understands.

Think of programming languages like different spoken languages—each has its own vocabulary and grammar rules. Just as you follow grammar rules when writing English sentences, you must follow syntax rules when writing code. Syntax is the set of rules that defines how to properly structure instructions in a programming language.

C++ is one such programming language. It's widely used for building games, applications, and systems software. Like English has rules about sentence structure (subject-verb-object), C++ has rules about how to write valid instructions.

Your First Look at Code

Here's the simplest C++ program you can write:

#include <iostream>

int main() {
    std::cout << "Hello, World!" << std::endl;
    return 0;
}

Don't worry if this looks confusing right now. You're about to write this exact code yourself and see it run. Before doing that, let's understand what it does at a high level.

This program does one thing: it displays the text "Hello, World!" on the screen. That's it. But to make that happen, you need all these parts working together according to C++'s rules.

Writing Your First Program in Outscal's Compiler

Now you'll write this program yourself and see it execute.

Step 1: Open Outscal's Online Compiler

• Go to https://outscal.com/online-compilers/cpp in your web browser
• You'll see an editor window (where you write code) and an output area (where results appear)

Step 2: Clear the Editor

• If there's any existing code in the editor, delete it so you have a blank space

Step 3: Type the Program Type exactly what you see below, including all punctuation marks. C++ is case-sensitive, meaning Main and main are different, so match the capitalization exactly:

#include <iostream>

int main() {
    std::cout << "Hello, World!" << std::endl;
    return 0;
}

Step 4: Run the Program

• Click the "Run" button in the compiler
• Look at the output area—you should see: Hello, World!

Congratulations! You just wrote and executed your first C++ program.

Experiencing the Feedback Loop

One of the best parts of programming is getting immediate feedback. Change the text inside the quotation marks to anything you want—your name, a message, anything. Keep the quotation marks, but change what's between them:

std::cout << "I just wrote my first program!" << std::endl;

Run it again. The program now displays your custom message. This is the programming feedback loop: write code → run it → see results. You'll use this loop constantly as you build your Tic-Tac-Toe game.

Why Syntax Rules Matter

Try this experiment: remove the semicolon at the end of the cout line and run the program. You'll get an error message—the program won't run. This happens because you broke one of C++'s syntax rules: every statement must end with a semicolon (;).

Put the semicolon back and run it again—it works. This demonstrates why syntax matters: even a single missing character prevents the entire program from running. Programming languages are precise and unforgiving, but this strictness helps catch mistakes early.

When you get error messages (and you will—every programmer does), they're the compiler's way of saying "You broke a syntax rule here." Read the error, fix the mistake, and try again.

What You've Accomplished

You now understand that programs are written in programming languages with specific syntax rules. You've experienced writing actual C++ code, running it, seeing output on the screen, and feeling the immediate satisfaction of making a computer do what you told it to do.

More importantly, you've crossed a threshold: you're no longer just learning about programming—you're actually programming.

What's Next

You successfully wrote and ran a Hello World program, but what do all those parts actually mean? Why #include, why main(), what's std::cout doing? In the next section, you'll understand each component's purpose without getting lost in overwhelming technical details.