SyntaxError: missing ; after for-loop initializer

$.ajax({
    url: "<%=request.getContextPath()%>/student/timeByDate.html",
    method: "post",
    data: "date=" + $(obj).text().trim(),
    success: function (json) {
        console.log(json);
        for(int j=0;j<json.length;j++){  //定义类型时写成了int ，应该是var
            console.log(json[j]);
        }
    }


})