Uboreshaji wa Operesheni Zilizorudiwa katika JavaScript
Mara nyingi waanzilishi wa programu hufanya wito wa kazi ile ile bila kufikiri mara kadhaa, wakitumia rasilimali.
Wacha tuangalie kwa mfano. Hebu tuseme tuna mfuatano ulio na njia fulani:
let path = 'img.png';
Hebu tuseme lengo letu ni kuangalia
kama njia inaisha kwa kiendelezi
.png au .jpg. Baadhi ya
waanzilishi wa programu waliandika
ufumbuzi ufuatao:
let path = 'img.png';
if (path.slice(-4) === '.png' || path.slice(-4) === '.jpg') {
console.log('+++');
} else {
console.log('---');
}
Nini kibaya na ufumbuzi huu? Shida ni
kwamba, mbinu slice inaitwa mara mbili,
ikifanya kitu kilekile. Hii, bila shaka,
sio bora.
Ili kuboresha, inahitajika kukata mfuatano mara moja, andika matokeo kwenye kutofautisha, kisha tumia kutofautisha hiyo baadaye:
let path = 'img.png';
let ext = path.slice(-4);
if (ext === '.png' || ext === '.jpg') {
console.log('+++');
} else {
console.log('---');
}
Boresha kificho kilio chini:
let num = 123;
if (String(num)[0] === '1' || String(num)[0] === '2') {
console.log('+++');
} else {
console.log('---');
}
Boresha kificho kilio chini:
let date = new Date();
if (date.getDay() === 0 || date.getDay() === 6) {
console.log('weekend');
} else {
console.log('weekday');
}
Boresha kificho kilio chini:
let date = new Date();
let res;
if (date.getFullYear() >= 2020 && date.getFullYear() <= 2030) {
res = 'mwaka ' + date.getFullYear() + ' unafaa';
} else {
res = 'mwaka ' + date.getFullYear() + ' haufai';
}
console.log(res)