Javascript 如何指定此随机图像脚本

Javascript 如何指定此随机图像脚本,javascript,Javascript,我用javascript在点击时显示一个随机图像: function pickimg(){ var imagenumber = 4 ; var randomnumber = Math.random() ; var rand1 = Math.round( (imagenumber-1) * randomnumber) + 1; images = new Array images[1] = "images/1.png" images[2] = "images/2.png" images[3] = "

我用javascript在点击时显示一个随机图像:

function pickimg(){
var imagenumber = 4 ;
var randomnumber = Math.random() ;
var rand1 = Math.round( (imagenumber-1) * randomnumber) + 1;
images = new Array
images[1] = "images/1.png"
images[2] = "images/2.png"
images[3] = "images/3.png"
images[4] = "images/4.png"
var image = images[rand1]
document.randimg.src = image

有没有办法确保同一个图像不会连续出现两次?

这个小算法怎么样

  • 将上次使用的图像存储在阵列的插槽0中
  • 选择索引大于0的随机图像
  • 展示它
  • 将其替换为插槽0中的图像
  • Javascript:

     images = new Array();
     images[0] = "images/1.png" //will be that last used image
     images[1] = "images/2.png"
     images[2] = "images/3.png"
     images[3] = "images/4.png"
     function pickimg(){
         var randomnumber = Math.random();
         // pick a random number from 1 to LENGTH (3)
         var rand1 = Math.round( (images.length-1) * randomnumber)+1;
         var image = images[rand1]; //get the image
    
        // switch so that the random image will be in the used
        // images slot (slot 0)
        images[rand1] = images[0] 
        images[0] = image 
    
        document.randimg.src = image
    }
    

    您可以创建一个数组并执行
    array.search(图像)!=-1
    您可以保留当前元素并检查它是否为sameThanks,以获得帮助。这似乎是可行的,但有时它会给出一个空白图像,上面写着“未定义”?