如何解决学习java找不到符号的问题？
如何解决学习java找不到符号的问题？
提问于 2018-08-22 06:55:42
以下是我使用的代码：
class Back {
void Backwards(String s) {
if (s.length = 0) {
System.out.println();
return;
}
System.out.print(s.charAt(s.length));
s = s.substring(0, s.length-1);
Backwards(s);
}
}
class RTest {
public static void main(String args[]) {
Back b;
b.Backwards("A STRING");
}}
输出：
john@fekete:~/javadev$ javac Recur.java
Recur.java:3: error: cannot find symbol
if (s.length = 0) {
^
symbol: variable length
location: variable s of type String
Recur.java:7: error: cannot find symbol
System.out.print(s.charAt(s.length));
^
symbol: variable length
location: variable s of type String
Recur.java:8: error: cannot find symbol
s = s.substring(0, s.length-1);
^
symbol: variable length
location: variable s of type String
3 errorsclass Back {
static void backwards(String s) {
if (s.length() == 0) {
System.out.println();
return;
}
System.out.print(s.charAt(s.length()-1));
s = s.substring(0, s.length()-1);
backwards(s);
}
}
class RTest {
public static void main(String args[]) {
Back.backwards("A STRING");
}
} 回答 2
Stack Overflow用户
发布于 2018-08-22 15:23:28
写成这样：
s.length() == 0 // it's a method, not an attributeStack Overflow用户
发布于 2018-08-22 16:13:10
试试以下代码：
public class StringTool {
public static String reverse(String source) {
// stop condition of the recursion
if (source.isEmpty()) {
return "";
}
int lastPosition = source.length() - 1;
String lastCharacter = source.charAt(lastPosition);
String restOfSource = source.substring(0, lastPosition);
// place the last character at the beginning and reverse the rest
// of the source recursively
return lastCharacter + reverse(restOfSource);
}
// test method
public static void main(String args[]) {
System.out.println(reverse("A STRING"));
}
} 页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/-100002361
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