SOURCE

var a = ["https:\/\/qiniu.crmeb.net\/attach\/2021\/10\/18\/3c0df4e754fff43d0e4dc4d401d6f112.jpg", "https:\/\/qiniu.crmeb.net\/attach\/2021\/10\/18\/840e97de4ae09ac53753c259c10ce718.jpg", "https:\/\/qiniu.crmeb.net\/attach\/2021\/10\/18\/6af7ce34c09e1e404b4df240b0fc0d6f.jpg", "https:\/\/qiniu.crmeb.net\/attach\/2021\/10\/18\/2e7c33a8b9240ec960852e80d5dbd419.jpg", "https:\/\/qiniu.crmeb.net\/attach\/2021\/10\/18\/1c98d79ab9647c6eb7f075f3a21f9fed.jpg", "https:\/\/qiniu.crmeb.net\/attach\/2021\/10\/18\/1f68c8d029ef9dd80b9a368394aaf54e.jpg"];

        var arr = [1, 1, 2, 12, 3, 23, 5, 6, 45]; //数组
      
        var c = [];//通过内容来获取的数组的下标
        //获取下标
        for (var i = 0; i < arr.length; i++) {
        
                c.push(i)
            
        }
        console.log(c)