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Practice

Creating a Carousel Function 1

In this lesson, we will be creating the functionality of a carousel using JavaScript.


Initial Setup​

Initial Setup
let slideIndex = 1;

showSlides(slideIndex);

Before diving into the main functionality of the carousel, we need to do some initial setup.

First, we declare a variable called slideIndex to store the index of the currently displayed slide.

Initially, we set the value of slideIndex to 1 so that the first slide is displayed.

Then, we call a function named showSlides.

We pass the value of slideIndex as an argument to this function.

This function is responsible for displaying the slides, and the slide displayed will depend on the value of the argument.

Here, since the value of slideIndex is 1, the first slide is displayed.


Creating the Slide Transition Functionality​

Creating Previous/Next Buttons
<a class="prev" onclick="plusSlides(-1)">&#10094;</a>
<a class="next" onclick="plusSlides(1)">&#10095;</a>

We have structured the carousel and created the previous/next buttons.

Now, we need to implement the functionality such that the slides transition when these buttons are clicked.

Declaring the plusSlides Function to Handle Slide Transition
function plusSlides(n) {
    showSlides(slideIndex += n);
}

The previously mentioned showSlides function is designed to display the slides based on the value of its argument.

The plusSlides function is implemented to call the showSlides function.

However, when calling the showSlides function, the value of slideIndex is increased by n.

Therefore, if the value of n is 1, the value of slideIndex is incremented by 1, and if the value of n is -1, the value of slideIndex is decremented by 1.

In this way, the value of slideIndex changes, causing the slides to transition.

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