uniapp 银行卡账号中间数字用*替换

cardreplace: function(cardno) {
    var str_array = cardno.split("");
    for (var i = 1; i < str_array.length - 4; i+=1) {
        if( i >= 4 && i<=str_array.length-4){
              str_array[i] = '*'
        }
    }
    var newArr = '';
    newArr = str_array.join("");
    return newArr;
 }