为什么在这行代码中不替换所有工作？[重复]

Question

    String weatherLocation = weatherLoc[1].toString();
weatherLocation.replaceAll("how","");
weatherLocation.replaceAll("weather", "");
weatherLocation.replaceAll("like", "");
weatherLocation.replaceAll("in", "");
weatherLocation.replaceAll("at", "");
weatherLocation.replaceAll("around", "");
test.setText(weatherLocation);

weatherLocation仍然包含“like in”

Answer 1

正如Rohit Jain所说，而且，由于replaceAll采用正则表达式，您可以简单地执行以下操作，而不是链接调用

test.setText(weatherLocation.replaceAll("how|weather|like|in|at|around", ""));

Answer 2

正如Rohit Jain所说，字符串是不可变的；在您的情况下，您可以将调用链接到replaceAll，以避免多次做作。

String weatherLocation = weatherLoc[1].toString()
        .replaceAll("how","")
        .replaceAll("weather", "")
        .replaceAll("like", "")
        .replaceAll("in", "")
        .replaceAll("at", "")
        .replaceAll("around", "");
test.setText(weatherLocation);

Answer 3

字符串是不可变的String#replaceAll（）方法将创建一个新字符串。您需要将结果重新分配回变量：

weatherLocation = weatherLocation.replaceAll("how","");

现在，由于replace eAll方法返回修改后的字符串，您还可以在一行中链接多个replace eAll调用。实际上，这里不需要replace eAll（）。当您要替换匹配正则表达式模式的子字符串时，这是必需的。简单地使用字符串#替换（）方法：

weatherLocation = weatherLocation.replace("how","")
                                 .replace("weather", "")
                                 .replace("like", "");