Devs-Mentoring.pl - Operators JS
javascript
a month ago
638 B
7
Indexable
Never
// Optional chaining (?.) const mentee = { name: 'Casper', training: { name: 'JS' }, }; const menteeName = mentee.nonexistingfield?.name; console.log(menteeName); // Wyświetli: undefined, zamiast rzucić exception TypeError console.log(mentee.nonexistingmethod?.()); // Wyświetli: undefined, zamiast rzucić exception TypeError // Nullish coalescing (??) const mentorName = null ?? 'Adam'; console.log(mentorName); // Wyświetli: 'Adam' const menteeName = 'Agata' : undefined; console.log(menteeName); // Wyświetli: 'Agata' const trainingName = 'Python' ?? 'JS'; console.log(trainingName); // Wyświetli: 'Python'