diff --git a/README.md b/README.md index 4d75bfd..d40099d 100644 --- a/README.md +++ b/README.md @@ -16,7 +16,6 @@ Lessons: Work in progress: -- use attributes or functions from a function within an object - constructors - encapsulation - getter / setter / property diff --git a/cpp/classes/README.md b/cpp/classes/README.md new file mode 100644 index 0000000..9f64d7c --- /dev/null +++ b/cpp/classes/README.md @@ -0,0 +1,9 @@ +# Classes in C++ + +In c++ classes are defined using a header file and the implementation in a +regular .cpp file. Explanations to the structure can be found in the files themselves + +## Relevant files + +- [car.h](./car.h) +- [car.cpp](./car.cpp) diff --git a/cpp/classes/car.cpp b/cpp/classes/car.cpp new file mode 100644 index 0000000..fd3e36a --- /dev/null +++ b/cpp/classes/car.cpp @@ -0,0 +1,23 @@ +// include the header file +#include "car.h" + +// include necessary libraries and namespaces +#include +#include +using namespace std; + +// define the implementation for car.print_info() +void car::print_info() +{ + cout << "Car Information:" << endl; + // fields that are defined in the header file can just be used like normal variables here + cout << "- manufacturer: " << manufacturer << endl; + cout << "- model: " << model << endl; +} + +/* + +That's everything for the .cpp file. +Since fields don't have an implementation and are already defined in the header file, they can be left out here. + +*/ \ No newline at end of file diff --git a/cpp/classes/car.h b/cpp/classes/car.h new file mode 100644 index 0000000..5dc8c02 --- /dev/null +++ b/cpp/classes/car.h @@ -0,0 +1,40 @@ +// #pragma once is usually included in header files to make sure they are only loaded once +// it's a simpler version of include guards, which are necessary to prevent conflicts +#pragma once +/* + +in case #pragma once is not supported by your compiler you'll need more basic include guards +in this case it would be +#ifndef car_h +#define car_h + +...class contents + +#endif + +*/ + +// including a necessary library and namespace to work with strings +#include +using namespace std; + +// define the class +class car +{ + // define the visibility of the following fields and methods + // in this case everything is public since visibility is a topic in future lessons + public: + // define two strings, manufacturer and model + std::string manufacturer; + std::string model; + + // define a function that will print out information + void print_info(); +}; + +/* + +That completes the header file, as you can see, there are no implementations in here. +That's because they will be added in the car.cpp file. + +*/ diff --git a/cpp/classes/main.cpp b/cpp/classes/main.cpp new file mode 100644 index 0000000..e848151 --- /dev/null +++ b/cpp/classes/main.cpp @@ -0,0 +1,20 @@ +#include "car.h" +#include + +int main() { + // create a new car and store it in the variable 'a' + // in contrast to java, c++ does not need initialization with the 'new' keyword here. + car a; + // set some data for that car + a.manufacturer = "Benz"; + a.model = "Velo"; + + // do the same for a second car + car b; + b.manufacturer = "Ford"; + b.model = "Model T"; + + // use a function of the car class to print out the information + a.print_info(); + b.print_info(); +} diff --git a/java/classes/Car.java b/java/classes/Car.java new file mode 100644 index 0000000..b5f40c8 --- /dev/null +++ b/java/classes/Car.java @@ -0,0 +1,18 @@ +/** + * this class is also declared with the public keyword to make it accessible + * outside of the current file + */ +public class Car { + public String model = ""; + public String manufacturer = ""; + + public void print_info() { + System.out.println("Car Information:"); + /** + * To access fields of the current object the this keyword is used. It is + * possible to omit that keyword, but it's recommended to be used anyways. + */ + System.out.println("- manufacturer: " + this.manufacturer); + System.out.println("- model: " + this.model); + } +} diff --git a/java/classes/README.md b/java/classes/README.md new file mode 100644 index 0000000..8bbaae1 --- /dev/null +++ b/java/classes/README.md @@ -0,0 +1,5 @@ +# Java Example + +Relevant Files: + +- [Car.java](./Car.java) diff --git a/java/classes/main.java b/java/classes/main.java new file mode 100644 index 0000000..e221455 --- /dev/null +++ b/java/classes/main.java @@ -0,0 +1,18 @@ +public class main { + public static void main(String[] args) { + // create a new car and store it in the variable 'a' + Car a = new Car(); + // set some data for that car + a.manufacturer = "Benz"; + a.model = "Velo"; + + // do the same for a second car + Car b = new Car(); + b.manufacturer = "Ford"; + b.model = "Model T"; + + // use a function of the car class to print out the information + a.print_info(); + b.print_info(); + } +} diff --git a/lessons/Classes.md b/lessons/Classes.md index 04df149..6469a1a 100644 --- a/lessons/Classes.md +++ b/lessons/Classes.md @@ -1,14 +1,25 @@ # Creating Classes -This lesson is going to use the same code from last time to explain -the class structure itself. +This lesson is going to use the same code from last time to explain the class +structure itself. -Since the example languages can have quite different styles of -class declaration, I will just give a basic explanation here and then -discuss every language in detail in their own description file. +Since the example languages can have quite different styles of class +declaration, I will just give a basic explanation here and then discuss every +language in detail in their own description file. -Classes are blueprints for the objects you create. You define how the -object will look like and more importantly for the computer how much -space it will use in memory. +Classes are blueprints for the objects you create. You define how the object +will look like and more importantly for the computer how much space it will use +in memory. +The main parts of a class are fields and methods. One for storing data and one +for processing that data. Fields are placed at the top of the class and look +like general variable declarations. Methods can take in arguments and also use +the fields declared in the class. They can modify data in the object or just +return some data to the caller. +## Code examples and language specific explanations + +- [Java](../java/classes/README.md) +- [Rust](../rust/classes/README.md) +- [C++](../cpp/classes/README.md) +- [JavaScript (using TypeScript)](../typescript/classes/README.md) diff --git a/rust/classes/Cargo.lock b/rust/classes/Cargo.lock new file mode 100644 index 0000000..3e2730f --- /dev/null +++ b/rust/classes/Cargo.lock @@ -0,0 +1,5 @@ +# This file is automatically @generated by Cargo. +# It is not intended for manual editing. +[[package]] +name = "rust-oop" +version = "0.1.0" diff --git a/rust/classes/Cargo.toml b/rust/classes/Cargo.toml new file mode 100644 index 0000000..2946813 --- /dev/null +++ b/rust/classes/Cargo.toml @@ -0,0 +1,9 @@ +[package] +name = "rust-oop" +version = "0.1.0" +authors = ["Timo Hocker "] +edition = "2018" + +# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html + +[dependencies] diff --git a/rust/classes/README.md b/rust/classes/README.md new file mode 100644 index 0000000..e0bc464 --- /dev/null +++ b/rust/classes/README.md @@ -0,0 +1,11 @@ +# Classes in Rust + +Rust doesn't have classes like Java or other typical c style languages. Instead +there are Structs and Traits. + +Structs are responsible for storing data and nothing else. Traits define +functions that can be used. + +## Relevant Files + +- [car.rs](./src/car.rs) diff --git a/rust/classes/src/car.rs b/rust/classes/src/car.rs new file mode 100644 index 0000000..0c6e4c0 --- /dev/null +++ b/rust/classes/src/car.rs @@ -0,0 +1,27 @@ +/* + * Define the trait Information that will contain the function print_info() + */ +pub trait Information { + // define the function, &self is an argument that will be autofilled + // when running the function and it will reference the current object + fn print_info(&self); +} + +/* + * Define the struct Car, which will hold all the necessary information + */ +pub struct Car { + pub manufacturer: String, + pub model: String +} + +/* + * Implementing the trait Information for the struct Car + */ +impl Information for Car { + fn print_info(&self) { + println!("Car Information:"); + println!("- manufacturer: {}", self.manufacturer); + println!("- model: {}", self.model); + } +} diff --git a/rust/classes/src/main.rs b/rust/classes/src/main.rs new file mode 100644 index 0000000..a7b4252 --- /dev/null +++ b/rust/classes/src/main.rs @@ -0,0 +1,23 @@ +mod car; +use car::Information; + +fn main() { + // create a new car and store it in the variable 'a' + // rust also doesn't use the 'new' keyword + // all attributes have to be defined upon creation of the object + let a = car::Car { + // set some data for that car + manufacturer: "Benz".to_string(), + model: "Velo".to_string() + }; + + // do the same for a second car + let b = car::Car { + manufacturer: "Ford".to_string(), + model: "Model T".to_string() + }; + + // use a function of the car class to print out the information + a.print_info(); + b.print_info(); +} diff --git a/typescript/classes/README.md b/typescript/classes/README.md new file mode 100644 index 0000000..ef91114 --- /dev/null +++ b/typescript/classes/README.md @@ -0,0 +1,5 @@ +# Typescript Example + +## Relevant Files + +- [car.ts](./car.ts) diff --git a/typescript/classes/car.ts b/typescript/classes/car.ts new file mode 100644 index 0000000..89da660 --- /dev/null +++ b/typescript/classes/car.ts @@ -0,0 +1,15 @@ +/** + * the class is defined with the export keyword to make it usable outside of the current file + */ +export class Car { + // define the fields + manufacturer: string = ''; + model: string = ''; + + // define the function print_info + print_info() { + console.log('Car Information:'); + console.log(`- manufacturer: ${this.manufacturer}`); + console.log(`- model: ${this.model}`); + } +} diff --git a/typescript/classes/index.ts b/typescript/classes/index.ts new file mode 100644 index 0000000..c80550f --- /dev/null +++ b/typescript/classes/index.ts @@ -0,0 +1,16 @@ +import {Car} from './car' + +// create a new car and store it in the variable 'a' +const a = new Car(); +// set some data for that car +a.manufacturer = 'Benz'; +a.model = 'Velo'; + +// do the same for a second car +const b = new Car(); +b.manufacturer = 'Ford'; +b.model = 'Model T'; + +// use a function of the car class to print out the information +a.print_info(); +b.print_info(); \ No newline at end of file diff --git a/typescript/classes/package.json b/typescript/classes/package.json new file mode 100644 index 0000000..22361fc --- /dev/null +++ b/typescript/classes/package.json @@ -0,0 +1,11 @@ +{ + "name": "ts-oop", + "version": "1.0.0", + "description": "", + "main": "index.js", + "scripts": { + "test": "echo \"Error: no test specified\" && exit 1" + }, + "author": "", + "license": "ISC" +} diff --git a/typescript/classes/tsconfig.json b/typescript/classes/tsconfig.json new file mode 100644 index 0000000..6232546 --- /dev/null +++ b/typescript/classes/tsconfig.json @@ -0,0 +1,66 @@ +{ + "compilerOptions": { + /* Basic Options */ + // "incremental": true, /* Enable incremental compilation */ + "target": "es5", /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019', 'ES2020', or 'ESNEXT'. */ + "module": "commonjs", /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', 'es2020', or 'ESNext'. */ + // "lib": [], /* Specify library files to be included in the compilation. */ + // "allowJs": true, /* Allow javascript files to be compiled. */ + // "checkJs": true, /* Report errors in .js files. */ + // "jsx": "preserve", /* Specify JSX code generation: 'preserve', 'react-native', or 'react'. */ + // "declaration": true, /* Generates corresponding '.d.ts' file. */ + // "declarationMap": true, /* Generates a sourcemap for each corresponding '.d.ts' file. */ + // "sourceMap": true, /* Generates corresponding '.map' file. */ + // "outFile": "./dist", /* Concatenate and emit output to single file. */ + "outDir": "./dist", /* Redirect output structure to the directory. */ + // "rootDir": "./", /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */ + // "composite": true, /* Enable project compilation */ + // "tsBuildInfoFile": "./", /* Specify file to store incremental compilation information */ + // "removeComments": true, /* Do not emit comments to output. */ + // "noEmit": true, /* Do not emit outputs. */ + // "importHelpers": true, /* Import emit helpers from 'tslib'. */ + // "downlevelIteration": true, /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */ + // "isolatedModules": true, /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */ + + /* Strict Type-Checking Options */ + "strict": true, /* Enable all strict type-checking options. */ + // "noImplicitAny": true, /* Raise error on expressions and declarations with an implied 'any' type. */ + // "strictNullChecks": true, /* Enable strict null checks. */ + // "strictFunctionTypes": true, /* Enable strict checking of function types. */ + // "strictBindCallApply": true, /* Enable strict 'bind', 'call', and 'apply' methods on functions. */ + // "strictPropertyInitialization": true, /* Enable strict checking of property initialization in classes. */ + // "noImplicitThis": true, /* Raise error on 'this' expressions with an implied 'any' type. */ + // "alwaysStrict": true, /* Parse in strict mode and emit "use strict" for each source file. */ + + /* Additional Checks */ + // "noUnusedLocals": true, /* Report errors on unused locals. */ + // "noUnusedParameters": true, /* Report errors on unused parameters. */ + // "noImplicitReturns": true, /* Report error when not all code paths in function return a value. */ + // "noFallthroughCasesInSwitch": true, /* Report errors for fallthrough cases in switch statement. */ + + /* Module Resolution Options */ + // "moduleResolution": "node", /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */ + // "baseUrl": "./", /* Base directory to resolve non-absolute module names. */ + // "paths": {}, /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */ + // "rootDirs": [], /* List of root folders whose combined content represents the structure of the project at runtime. */ + // "typeRoots": [], /* List of folders to include type definitions from. */ + // "types": [], /* Type declaration files to be included in compilation. */ + // "allowSyntheticDefaultImports": true, /* Allow default imports from modules with no default export. This does not affect code emit, just typechecking. */ + "esModuleInterop": true, /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */ + // "preserveSymlinks": true, /* Do not resolve the real path of symlinks. */ + // "allowUmdGlobalAccess": true, /* Allow accessing UMD globals from modules. */ + + /* Source Map Options */ + // "sourceRoot": "", /* Specify the location where debugger should locate TypeScript files instead of source locations. */ + // "mapRoot": "", /* Specify the location where debugger should locate map files instead of generated locations. */ + // "inlineSourceMap": true, /* Emit a single file with source maps instead of having a separate file. */ + // "inlineSources": true, /* Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set. */ + + /* Experimental Options */ + // "experimentalDecorators": true, /* Enables experimental support for ES7 decorators. */ + // "emitDecoratorMetadata": true, /* Enables experimental support for emitting type metadata for decorators. */ + + /* Advanced Options */ + "forceConsistentCasingInFileNames": true /* Disallow inconsistently-cased references to the same file. */ + } +}