javascript - 用javascript替换多个图像之一

Question

我有多个相同的图像。当我单击其中一个时，需要更换 img。我有 JS 脚本：

var newsrc = "slide_down";
function changeImage() {
    if ( newsrc == "slide_down" ) {
        document.images["pic"].src = "img/slide_up.png";
        document.images["pic"].alt = "slide_up";
        newsrc  = "slide_up";
    }
    else {
        document.images["pic"].src = "img/arrow.png";
        document.images["pic"].alt = "slide_down";
        newsrc  = "slide_down";
    }
}

但是当我按第二个img时，总是第一个被替换。请帮忙。图片的HTML代码是<img src="img/arrow.png" alt="slide_up" class="head" id="pic" onclick="changeImage()">

Answer 1

尝试

var newsrc = "slide_down";
function changeImage() {
    if ( newsrc == "slide_down" ) {
       this.src = "img/slide_up.png";
        this.alt = "slide_up";
        newsrc  = "slide_up";
    }
    else {
        this.src = "img/arrow.png";
        this.alt = "slide_down";
        newsrc  = "slide_down";
    }
}