Question

if(containsAllWeather || containsAllWeather2){

            String weatherLocation = value.toString();

        if (weatherLocation != null){


                weatherLocation.replaceAll("how","")
                        .replaceAll("what","")
                        .replaceAll("weather", "")
                        .replaceAll("like", "")
                        .replaceAll(" in", "")
                        .replaceAll(" at", "")
                        .replaceAll("around", "");
        }

weatherLocation仍然提供变量 value 所包含的内容，并且不会删除上面列出的任何单词。

当我将weatherLocation拆分为一个字符串数组时，例如，weatherLoc数组，以及那些为weatherLoc工作的代码行[1]

我做错了什么？

Answer 1

您需要将方法调用返回的值分配回String引用变量。每次执行replaceAll()时，它都会返回新 String对象，但您的weatherLocation变量仍然引用原始字符串。

  weatherLocation = weatherLocation.replaceAll("how","")
                    .replaceAll("what","")
                    .replaceAll("weather", "")
                    .replaceAll("like", "")
                    .replaceAll(" in", "")
                    .replaceAll(" at", "")
                    .replaceAll("around", "");

Answer 2

字符串是不可变的。您需要将所有这些replaceAll调用的值分配给变量，这将是您想要的。

weatherLocation = weatherLocation.replaceAll("how","")
                .replaceAll("what","")
                .replaceAll("weather", "")
                .replaceAll("like", "")
                .replaceAll(" in", "")
                .replaceAll(" at", "")
                .replaceAll("around", "");

Answer 3

试试这个：

weatherLocation = weatherLocation.replaceAll("how","")
                        .replaceAll("what","")
                        .replaceAll("weather", "")
                        .replaceAll("like", "")
                        .replaceAll(" in", "")
                        .replaceAll(" at", "")
                        .replaceAll("around", "");

Answer 4

String是immutable。因此，String.replaceAll会返回instance的新String。所以你需要使用如下

weatherLocation = weatherLocation.replaceAll("how","")
                .replaceAll("what","")
                .replaceAll("weather", "")
                .replaceAll("like", "")
                .replaceAll(" in", "")
                .replaceAll(" at", "")
                .replaceAll("around", "");

无法使用replaceAll从字符串中删除单词

4 个答案: