Week 1 Review & Practice

Week 1 Wrap-up

Congratulations! You’ve completed the first week of Go Basics in 30 Days. You’ve gone from “Hello World” to understanding the core syntax that makes Go unique.

What We’ve Covered

• Day 1: Introduction to Go, environment setup, and your first program.
• Day 2: Variables, constants, and basic data types (int, float, string, bool).
• Day 3: Operators (arithmetic, comparison, logical) and expressions.
• Day 4: Conditionals with if, else if, else, and switch.
• Day 5: The versatile for loop, break, continue, and range.
• Day 6: Functions, multiple return values, and variadic functions.

Practice Project: The Multi-Tool CLI

To solidify your knowledge, we’re going to build a small command-line tool that performs various calculations and conversions. This project will use everything you’ve learned so far.

Project Requirements

Create a program that:

1. Shows a menu of options to the user.
2. Accepts user input for choices and values.
3. Implements the following features:
   • Temperature Converter: Celsius to Fahrenheit and vice versa.
   • Basic Calculator: Addition, subtraction, multiplication, and division.
   • Grade Calculator: Takes a numeric score and returns a letter grade.
   • Leap Year Checker: Determines if a year is a leap year.
4. Uses functions for each feature.
5. Uses a loop to allow the user to perform multiple operations until they choose to exit.

Implementation Guide

Here’s a starting point for your main.go:

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package main

import (
    "fmt"
)

func showMenu() {
    fmt.Println("\n--- Week 1 Multi-Tool ---")
    fmt.Println("1. Temperature Converter")
    fmt.Println("2. Basic Calculator")
    fmt.Println("3. Grade Calculator")
    fmt.Println("4. Leap Year Checker")
    fmt.Println("0. Exit")
    fmt.Print("Choose an option: ")
}

func main() {
    for {
        showMenu()
        
        var choice int
        fmt.Scan(&choice)
        
        if choice == 0 {
            fmt.Println("Goodbye!")
            break
        }
        
        switch choice {
        case 1:
            runTempConverter()
        case 2:
            runCalculator()
        case 3:
            runGradeCalculator()
        case 4:
            runLeapYearChecker()
        default:
            fmt.Println("Invalid choice, try again.")
        }
    }
}

// Implement the run... functions below!

Tips for Implementation

• Use fmt.Scan(&variable) to get user input.
• For the calculator, return an error if the user tries to divide by zero.
• Use switch for the menu and the calculator operations.
• Remember to use float64 for temperature and division results.

Self-Check Quiz

Before you move on to Week 2, ask yourself:

1. Can I declare variables using both var and :=?
2. Do I understand when to use int vs float64 vs string?
3. Can I write a loop that skips even numbers?
4. Do I feel comfortable returning multiple values from a function?
5. Can I handle basic user input using fmt.Scan?

If you answered “Yes” to all, you’re ready for Week 2!

Summary

This week was all about the foundations. While you haven’t seen everything Go has to offer yet, you now have the tools to write basic functional programs.

Next Steps

In Week 2, we’ll dive into Data Structures. We’ll move beyond simple variables and learn about:

• Arrays and Slices (dynamic arrays)
• Maps (key-value pairs)
• Structs (custom data types)
• Pointers (memory addresses)

Complete the final Week 1 review quiz to unlock Week 2!