- Collaborative JavaScript Debugging
- JavaScript Debugging
- Projektordner für den Test von JavaScript-Snippets
- Code Sandbox, Online Code Editor
- The online code editor for Web
- Start eines Basis-Templates (Vanilla)
// Variante 1 class Car {} class Audi extends Car {} let a = new Audi(); console.log(a instanceof Car); // Variante 2 let arr = [1, 2, 3]; console.log(arr instanceof Object); console.log(arr instanceof Array);
// https://www.w3schools.com/js/js_errors.asp try { // Fehler oops(); } catch(e) { // komplette Message console.log(e); // Fehlername console.log(e.name); // Message console.log(e.message); // Aufrufstack console.log(e.stack); } finally { console.log("Finally."); }
// https://www.w3schools.com/js/js_errors.asp // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error try { throw new Error("Ein Error."); // throw new EvalError("Ein EvalError."); // throw new RangeError("Ein RangeError."); // throw new ReferenceError("Ein ReferenceError."); // throw new SyntaxError("Ein SytaxError."); // throw new TypeError("Ein TypeError."); // throw new URIError("Ein URIError."); } catch(e) { console.log(e); }
// Klasse Array erweitern class Stack extends Array { get first() { return this[0]; } get last() { return this[this.length - 1]; } } var stack = new Stack(); stack.push('Udo'); stack.push('Horst'); // Udo console.log(stack.first); // Horst console.log(stack.last);
// ab ES6 class Car { } class Audi extends Car { } // true console.log(Object.getPrototypeOf(Audi) === Car);
// https://javascript.info/class-inheritance // https://developer.mozilla.org/de/docs/Web/JavaScript/Reference/Klassen // ab ES6 class Car { constructor(name) { this.name = name; } drive() { console.log("Driving: " + this.name); } } class Audi extends Car { quadro() { console.log("Quadro: " + this.name); } } let a = new Audi("A4"); a.drive(); a.quadro();
https://javascript.info/property-descriptors let user = { name: "Ede", city: "Berlin" }; let descriptor = Object.getOwnPropertyDescriptor(user, 'city'); console.log(JSON.stringify(descriptor, null, 2));
let a = 5; let b = 7; // Verwendung von Backticks -> Einbindung von Ausdrücken let str = `${a} + ${b} = ${a+b}`; // 5 + 7 = 12 console.log(str);
// https://javascript.info/json // JSON-Objekt definieren let sJSON = '{ "name":"Heinz","age":"56","city":"Hamburg" }'; // JSON-Objekt aus String parsen let oJSONpar = JSON.parse(sJSON); // Testausgabe console.log(oJSONpar.name);
// JSON-Objekt definieren let sJSON = '{ "name":"Heinz","age":"56","city":"Hamburg","birth":"2018-04-25T12:00:00.000Z" }'; // JSON-Objekt aus String parsen let oJSONpar = JSON.parse(sJSON, function(key, value) { // wenn Datumsfeld "birth" if (key == 'birth') { // Datumsobjekt zurückgeben return new Date(value); } else { return value; }; }); // Geburtsdatum ist jetzt vom Typ "Date" mit enspr. Funktionen console.log(oJSONpar.birth.toLocaleString('de-DE'));