小编mar*_*ary的帖子

我在反应中有这个问题我有这个功能，但它的反应格式不正确

check(img) {
        console.log(img,typeof img)
        const url="";
        const arrN = ["15","16","35","36","37","38","39","40","n15","n16","n35","n36","n37","n38","n39","n40"];
        for (var i = 0; i < arrN.length; i++) {
            if (img === arrN[i]) {
                 url = "/blah/allIcons/blah"+img+"_en.png";
            }else{
                 url = "/blah/allIcons/blah"+img+".png";
            }
        }
        return url;
    }

它给了我这个错误

Module build failed: SyntaxError: "url" is read-only

我该怎么做？