Variables, Constants, Expressions, and Equations

/**
 * Fintech Math Bootcamp · Lesson 001 of 120
 * Variables, Constants, Expressions, and Equations
 * Module 01: Mathematical Language and Quantitative Reasoning
 *
 * Scenario: A wallet reconciliation that actually balances
 * Rule:     ending = opening + inflows − outflows
 *
 * Try it:   What happens if outflows become 200?
 *
 * Lesson article: https://thefintechbuilder.com/financial-mathematics-statistics-and-data-foundations/mathematical-language-and-quantitative-reasoning/variables-constants-expressions-and-equations/
 * Free course:    https://courses.thefintechbuilder.com
 * Synthetic teaching example, not financial advice or a production library.
 */

export function lesson001() {
  const opening = 1000;
  const inflows = 250;
  const outflows = 120;
  const ending = opening + inflows - outflows;
  const result = ending;
  return result;
}

export const checkedResult = 1130;

// Run this file directly: npx tsx lessons/01-mathematical-language-and-quantitative-reasoning/001-variables-constants-expressions-and-equations.ts
if (process.argv[1] && import.meta.url.endsWith(process.argv[1].replace(/\\/g, "/").split("/").pop()!)) {
  console.log(JSON.stringify(lesson001(), null, 2));
}

"""
Fintech Math Bootcamp · Lesson 001 of 120
Variables, Constants, Expressions, and Equations
Module 01: Mathematical Language and Quantitative Reasoning

Scenario: A wallet reconciliation that actually balances
Rule:     ending = opening + inflows − outflows

Try it:   What happens if outflows become 200?

Lesson article: https://thefintechbuilder.com/financial-mathematics-statistics-and-data-foundations/mathematical-language-and-quantitative-reasoning/variables-constants-expressions-and-equations/
Free course:    https://courses.thefintechbuilder.com
Synthetic teaching example, not financial advice or a production library.

Run it: python main.py
"""

import json


def lesson001() -> float:
    opening = 1000
    inflows = 250
    outflows = 120
    ending = opening + inflows - outflows
    result = ending
    return result


if __name__ == "__main__":
    print(json.dumps(lesson001(), indent=2))

/**
 * Fintech Math Bootcamp · Lesson 001 of 120
 * Variables, Constants, Expressions, and Equations
 * Module 01: Mathematical Language and Quantitative Reasoning
 *
 * Scenario: A wallet reconciliation that actually balances
 * Rule:     ending = opening + inflows − outflows
 *
 * Try it:   What happens if outflows become 200?
 *
 * Lesson article: https://thefintechbuilder.com/financial-mathematics-statistics-and-data-foundations/mathematical-language-and-quantitative-reasoning/variables-constants-expressions-and-equations/
 * Free course:    https://courses.thefintechbuilder.com
 * Synthetic teaching example, not financial advice or a production library.
 *
 * Run it: javac Main.java && java Main
 */

public class Main {
    static double lesson001() {
        double opening = 1000;
        double inflows = 250;
        double outflows = 120;
        double ending = opening + inflows - outflows;
        double result = ending;
        return result;
    }

    public static void main(String[] args) {
        System.out.println(num(lesson001()));
    }

    // Formats a double the way JSON.stringify does: whole numbers without ".0", null for NaN or infinity.
    static String num(double x) {
        if (Double.isNaN(x) || Double.isInfinite(x)) return "null";
        if (x == Math.rint(x) && Math.abs(x) < 1e15) return String.valueOf((long) x);
        return String.valueOf(x);
    }
}

// Fintech Math Bootcamp · Lesson 001 of 120
// Variables, Constants, Expressions, and Equations
// Module 01: Mathematical Language and Quantitative Reasoning
//
// Scenario: A wallet reconciliation that actually balances
// Rule:     ending = opening + inflows − outflows
//
// Try it:   What happens if outflows become 200?
//
// Lesson article: https://thefintechbuilder.com/financial-mathematics-statistics-and-data-foundations/mathematical-language-and-quantitative-reasoning/variables-constants-expressions-and-equations/
// Free course:    https://courses.thefintechbuilder.com
// Synthetic teaching example, not financial advice or a production library.
//
// Run it: go run main.go

package main

import (
	"encoding/json"
	"fmt"
)

func lesson001() float64 {
	opening := 1000.0
	inflows := 250.0
	outflows := 120.0
	ending := opening + inflows - outflows
	result := ending
	return result
}

func main() {
	printJSON(lesson001())
}

// printJSON prints a value as JSON indented with two spaces, like JSON.stringify(value, null, 2).
func printJSON(value any) {
	out, err := json.MarshalIndent(value, "", "  ")
	if err != nil {
		panic(err)
	}
	fmt.Println(string(out))
}

/**
 * Fintech Math Bootcamp · Lesson 001 of 120
 * Variables, Constants, Expressions, and Equations
 * Module 01: Mathematical Language and Quantitative Reasoning
 *
 * Scenario: A wallet reconciliation that actually balances
 * Rule:     ending = opening + inflows − outflows
 *
 * Try it:   What happens if outflows become 200?
 *
 * Lesson article: https://thefintechbuilder.com/financial-mathematics-statistics-and-data-foundations/mathematical-language-and-quantitative-reasoning/variables-constants-expressions-and-equations/
 * Free course:    https://courses.thefintechbuilder.com
 * Synthetic teaching example, not financial advice or a production library.
 *
 * Run it: g++ -std=c++17 -o main main.cpp && ./main
 */

#include <charconv>
#include <cmath>
#include <iostream>
#include <string>

// Formats a double the way JSON.stringify does: shortest round-trip form, null for NaN or infinity.
std::string num(double x) {
    if (!std::isfinite(x)) return "null";
    char buffer[32];
    auto [end, error] = std::to_chars(buffer, buffer + sizeof buffer, x);
    (void)error;
    return std::string(buffer, end);
}

double lesson001() {
    const double opening = 1000;
    const double inflows = 250;
    const double outflows = 120;
    const double ending = opening + inflows - outflows;
    const double result = ending;
    return result;
}

int main() {
    std::cout << num(lesson001()) << "\n";
}

//! Fintech Math Bootcamp · Lesson 001 of 120
//! Variables, Constants, Expressions, and Equations
//! Module 01: Mathematical Language and Quantitative Reasoning
//!
//! Scenario: A wallet reconciliation that actually balances
//! Rule:     ending = opening + inflows − outflows
//!
//! Try it:   What happens if outflows become 200?
//!
//! Lesson article: https://thefintechbuilder.com/financial-mathematics-statistics-and-data-foundations/mathematical-language-and-quantitative-reasoning/variables-constants-expressions-and-equations/
//! Free course:    https://courses.thefintechbuilder.com
//! Synthetic teaching example, not financial advice or a production library.
//!
//! Run it: rustc main.rs && ./main

fn lesson001() -> f64 {
    let opening = 1000.0;
    let inflows = 250.0;
    let outflows = 120.0;
    let ending = opening + inflows - outflows;
    let result = ending;
    result
}

fn main() {
    println!("{}", num(lesson001()));
}

/// Formats a number the way JSON.stringify does: shortest round-trip form, null for NaN or infinity.
fn num(x: f64) -> String {
    if x.is_finite() {
        format!("{}", x)
    } else {
        "null".to_string()
    }
}

/**
 * Fintech Math Bootcamp · Lesson 001 of 120
 * Variables, Constants, Expressions, and Equations
 * Module 01: Mathematical Language and Quantitative Reasoning
 *
 * Scenario: A wallet reconciliation that actually balances
 * Rule:     ending = opening + inflows − outflows
 *
 * Try it:   What happens if outflows become 200?
 *
 * Lesson article: https://thefintechbuilder.com/financial-mathematics-statistics-and-data-foundations/mathematical-language-and-quantitative-reasoning/variables-constants-expressions-and-equations/
 * Free course:    https://courses.thefintechbuilder.com
 * Synthetic teaching example, not financial advice or a production library.
 *
 * Run it: dotnet run  (inside a console project that holds this Program.cs)
 */

using System.Text.Json;

Console.WriteLine(JsonSerializer.Serialize(Lesson001()));

static double Lesson001()
{
    const double opening = 1000;
    const double inflows = 250;
    const double outflows = 120;
    const double ending = opening + inflows - outflows;
    const double result = ending;
    return result;
}