java字符串。replaceAll（）在我的looop中不工作

Question

因此，我试图删除电话号码中的所有特殊字符，只留下数字，不幸的是，它不起作用。我已经找到了其他解决方案，但它们仍然不起作用。即使在调试器中运行了它，它看起来仍然是。replaceAll（）方法只是不做任何事情。下面是我的代码：

if (c !=null) {
            //populate database with first 100 texts of each contact
            dbs.open();
            //comparator address, count to 100
            String addressX = "";
            int count = 0;
            c.moveToFirst();
            for (int i = 0; i < c.getCount(); i++) {
                //get c address
                String addressY = c.getString(c.getColumnIndex("address"));
                addressY.replaceAll("[^0-9]+", "").trim();
                //one for the address, other to be able to sort threads by date  !Find better solution!
                if (!smsAddressList.contains(addressY)) {
                    //custom object so listview can be sorted by date desc
                    String date = c.getString(c.getColumnIndex("date"));
                    smsDateList.add(date);
                    smsAddressList.add(addressY);
                }
                //less than 100 texts, add to database, update comparator, add to count
                if (count < 100) {
                    c.moveToPosition(i);
                        addText(c);
                        addressX = addressY;
                        count++;
                    }
                //if more 100 texts, check to see if new address yet
                else if (count>100) {
                    //if still same address, just add count for the hell of it
                    if (addressX.equals(addressY)) {
                        count++;
                    }
                    //if new address, add text, reset count
                    else {
                        addText(c);
                        addressX = addressY;
                        count = 1;
                    }


                }


            }
        }

Answer 1

确保将更改的字符串分配给addressY

addressY = addressY.replaceAll("[^0-9]+", "").trim();

Answer 2

addressY = addressY.replaceAll("[^0-9]+", "").trim();

replaceAll方法创建一个新字符串，因此需要重新分配变量

Answer 3

String.replaceAll()返回修改后的字符串，它不会在适当的位置修改字符串。所以你需要一些类似的东西：

addressY = addressY.replaceAll("[^0-9]+", "").trim();

我也非常确定trim在这里是多余的，因为您已经用replaceAll去除了空白。因此，您可以逃脱：

addressY = addressY.replaceAll("[^0-9]+", "");

Answer 4

字符串是不可变的replaceAll只返回带有所需修改的新字符串

您需要执行以下操作：

addressY = addressY.replaceAll("[^0-9]+", "").trim();