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:

javascriptlet 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:

javascriptlet 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:

javascriptlet path = 'img.png';
let ext  = path.slice(-4);

if (ext === '.png' || ext === '.jpg') {
  console.log('+++');
} else {
  console.log('---');
}

javascriptlet num = 123;

if (String(num)[0] === '1' || String(num)[0] === '2') {
  console.log('+++');
} else {
  console.log('---');
}

javascriptlet date = new Date();

if (date.getDay() === 0 || date.getDay() === 6) {
  console.log('weekend');
} else {
  console.log('weekday');
}

javascriptlet 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)