add topic_4

topic_4/example2/script.js

@@ -0,0 +1,27 @@
+let slideIndex = 1;
+
+showSlides(slideIndex);
+
+function nextSlide() {
+    showSlides(slideIndex += 1);
+}
+
+function previousSlide() {
+    showSlides(slideIndex -= 1);
+}
+
+function showSlides(n) {
+    let slides = document.getElementsByClassName("slider-line")[0].getElementsByTagName("img");
+
+    if (n > slides.length) {
+        slideIndex = 1
+    }
+    if (n < 1) {
+        slideIndex = slides.length
+    }
+
+    for (let slide of slides) {
+        slide.style.display = "none";
+    }
+    slides[slideIndex - 1].style.display = "block";
+}