java - 如何在 StringBuilder 中连接子字符串？

Question

如何将子字符串连接重构为StringBuilder？

        String line = "this is my start and my end string";
        int start = line.indexOf("start");
        line = line.substring(0, start) + line.substring(start + 5);

        int end = line.indexOf("end");
        line = line.substring(0, end) + line.substring(end + 3);
            //result: this is my and my string";

使用 StringBuilder 时，相同的代码会是什么样子？当我想一个接一个地多次执行子字符串时？

Answer 1

如果您的问题是“如何从字符串中反复删除子字符串”，您可以尝试以下操作：

StringBuilder line = new StringBuilder("this is my start and my end string");
int start = line.indexOf("start");
line.delete(start, start + 5);
int end = line.indexOf("end");
line.delete(end, end + 3);
String result = sb.toString()

创建一次 StringBuilder，然后操作其内容。

Answer 2

这样的事情可能是：

    StringBuilder line = new StringBuilder("this is my **start** and my **end** string");
    int start = line.indexOf("start");
    line = new StringBuilder(line.substring(0, start).append(line.substring(start + 5)));

    int end = line.indexOf("end");
    line = new StringBuilder(line.substring(0, end).append(line.substring(end + 3)));

Answer 3

你的意思是这样的吗？还是我理解错了？

String line = "this is my start and my end string";
int start = line.indexOf("start");
int end = line.indexOf("end");
StringBuilder sb = new StringBuilder();
sb.append(line.substring(0, start);
sb.append(line.substring(start + 5);
sb.append(line.substring(0, end);
sb.append(line.substring(end + 3);
String result = sb.toString()

Answer 4

如果我没记错的话，StringBuilder 有它自己的 indexOf 和子字符串实现。该问题的主要关注点似乎是放弃使用 String，而 StringBuilder 的主要功能仍然是串联。

所以http://docs.oracle.com/javase/7/docs/api/java/lang/StringBuilder.html可以帮助你找到相关的方法，你可以继续使用 StringBuilder 和 .append() 方法和你的字符串查找和子字符串方法。

Answer 5

尝试

String line = "this is my start and my end string";
    int start = line.indexOf("start");
    StringBuilder stringBuilder = new StringBuilder();
    stringBuilder.append(line.substring(0, start));
    stringBuilder.append(line.substring(start + 5));

    int end = line.indexOf("end");
    stringBuilder.append(line.substring(0, end));
    stringBuilder.append(line.substring(end + 3));
    System.out.println("StringBuilder : "+stringBuilder.toString());