Six languages, covered properly.

One complete Python course: the language itself, then the libraries and frameworks people actually use it for — NumPy, pandas, Django, databases, algorithms, and machine learning.

message = "Hello from Python"
print(message)

One complete JavaScript course: the language itself, then the browser — the DOM, events, fetch, storage, and the async model everything else is built on.

const message = "Hello from JavaScript";
console.log(message);

One complete Java course: syntax and types, then real object orientation, generics, collections, streams, concurrency, and the build and test tooling a Java job assumes.

public class Main {
    public static void main(String[] args) {
        System.out.println("Hello from Java");
    }
}

One complete C++ course in modern style: values and references, ownership and RAII, move semantics, templates, and the standard library — not C with classes.

#include <iostream>

int main() {
    std::cout << "Hello from C++" << '\n';
}

One complete C course built around the thing C is actually about: memory. Pointers, arrays, dynamic allocation, undefined behaviour, and multi-file builds.

#include <stdio.h>

int main(void) {
    printf("Hello from C\n");
    return 0;
}

One complete SQL course: querying, joins, aggregation, window functions, schema design, transactions, indexes, and the injection boundary every application crosses.

SELECT name, COUNT(*) AS orders
FROM customers
GROUP BY name
ORDER BY orders DESC;