圖像滑塊jQuery不起作用

Question

 $("#forward_carousel").click( () => { //sets timeout back and starts clearTimeout(timeout); timeout = 0; var i; var x = $(".carousel_size");//class for the pictures in carousel for (i = 0; i < x.length; i++) { x[i].style.display = "none"; } slideIndex++; if (slideIndex > x.length) {slideIndex = 1} x[slideIndex-1].style.display = "block"; timeout =setInterval(carousel, 5000); }) $("#backward_carousel").click( () => { clearTimeout(timeout); timeout = 0; var i; var x = $(".carousel_size");//class for the pictures in carousel for (i = 0; i < x.length; i++) { x[i].style.display = "none"; } slideIndex--; if (slideIndex < x.length){slideIndex = 3} x[slideIndex-1].style.display = "block"; timeout =setInterval(carousel, 5000); }) 

如果當前圖片在索引1處，則前進按鈕將起作用，但是后退按鈕將起作用。如果索引不為1，則后退按鈕將根本不起作用。

Answer 1

您的向后索引條件不正確。

更改此行：

 if (slideIndex < x.length){slideIndex = 3}

對此：

 if (slideIndex < 0){slideIndex = x.length}