JavaScript-da Faollashtirish Uslublarini Almashish

Oldingi darsda biz ustunlarni ularga bosganda faollashtirishni o‘rgandik. Keling, endi ranglarning almashinishi amalga oshiriladigan qilaylik: birinchi ustun qizil rangga, ikkinchisi - yashil rangga, uchinchisi - yana qizil va hokazo bo‘yaladi.

Bu masalani yechish uchun bizga allaqachon ikkita CSS klass kerak bo‘ladi:

css.color1 {
  background: red;
}
.color2 {
  background: green;
}

Keling, tavsiflangan almashinishni amalga oshiramiz:

javascriptlet tds = document.querySelectorAll('#table td');

let color = 'color1';
for (let td of tds) {
  td.addEventListener('click', function() {
    if (color == 'color1') {
      color = 'color2'
    } else {
      color = 'color1'
    }
    
    this.classList.add(color);
  });
}

Massivdan Ko‘p Ranglarni Almashish

Endi ikkita emas, balki ixtiyoriy miqdordagi ranglarni almashtirmoqchi bo‘lganimiz faraz qilaylik. Buning uchun CSS klasslar massivini saqlaymiz:

javascriptlet colors = ['color1', 'color2', 'color3'];

Keling, klasslarimizning ranglarini yozamiz:

css.color1 {
  background: red;
}
.color2 {
  background: green;
}
.color3 {
  background: yellow;
}

Endi esa almashinishni amalga oshiramiz:

javascriptlet tds = document.querySelectorAll('#table td');

let i = 0;
let colors = ['color1', 'color2', 'color3'];

for (let td of tds) {
  td.addEventListener('click', function() {
    this.classList.add(colors[i]);
    
    i++;
    if (i == colors.length) {
      i = 0;
    }
  });
}