IF ... THEN ... ELSE

4 tips for write cleaner code

Transcript

1. IF … THEN … ELSE Come sopravvivere alle avverse condizioni e vivere una vita più felice
2. 4 consigli per scrivere codice più pulito
3. 100% Utile anche per linguaggi che non siano JavaScript
4. 1. Multiple criteria
5. function test(fruit) { if (fruit == 'apple' || fruit == 'strawberry') console.log('red'); }
6. Array.includes
7. function test(fruit) { const redFruits = ['apple', 'strawberry', 'cherry', 'cranberries']; if (redFruits.includes(fruit)) console.log('red'); }
8. 2. Nesting
9. function test(fruit, quantity) { const redFruits = ['apple', 'strawberry', 'cherry', 'cranberries']; if (fruit) { if (redFruits.includes(fruit)) { console.log('red'); if (quantity > 10) console.log('big quantity'); } } else { throw new Error('No fruit!'); } }
10. Return Early
11. function test(fruit, quantity) { const redFruits = ['apple', 'strawberry', 'cherry', 'cranberries']; if (!fruit) throw new Error('No fruit!'); if (!redFruits.includes(fruit)) return; console.log('red'); if (quantity > 10) console.log('big quantity'); }
12. 3. Switch
13. function test(color) { switch (color) { case 'red': return ['apple', 'strawberry']; case 'yellow': return ['banana', 'pineapple']; case 'purple': return ['grape', 'plum']; default: return []; } }
14. Object Literal (Map)
15. const fruitColor = { red: ['apple', 'strawberry'], yellow: ['banana', 'pineapple'], purple: ['grape', 'plum'] }; function test(color) { return fruitColor[color] || []; }
16. 4. Partial criteria
17. const fruits = [ { name: 'apple', color: 'red' }, { name: 'banana', color: 'yellow' } ]; function test() { let isAllRed = true; for (let f of fruits) { if (f.color == 'red') { isAllRed = false; break; } } console.log(isAllRed); }
18. Array.every (Array.some)
19. const fruits = [ { name: 'apple', color: 'red' }, { name: 'banana', color: 'yellow' } ]; function test() { const isAllRed = fruits.every(f => f.color == 'red'); console.log(isAllRed); }
20. I linguaggi offrono più di quello che pensiamo
21. Studiamo Grazie per l’attenzione