I have -
import java.util.*;
public class TestCompare {
List<String> list = Arrays.asList("10", "1", "20", "11", "21", "12");
Comparator<String> cmp = new Comparator<String>() {
public int compare(String o1, String o2) {
return Integer.valueOf(o1).compareTo(Integer.valueOf(o2));
}
};
Collections.sort(list, cmp);
}
At Collections.sort(list, cmp); there is an error - Syntax error on token "(", delete this token. What is wrong in this syntax ?
You can't have code directly in a class, it should be in a method like main:
public class TestCompare {
public static void main() {
List<String> list = Arrays.asList("10", "1", "20", "11", "21", "12");
Comparator<String> cmp = new Comparator<String>() {
public int compare(String o1, String o2) {
return Integer.valueOf(o1).compareTo(Integer.valueOf(o2));
}
};
Collections.sort(list, cmp);
}
}
run... wizard
You need to wrap your code in a method, not directly in the class block.
At class level, only declarations (and initializer) blocks are allowed. Your first two statements are declarations (they are interpreted as field declarations, even though that is probably not your intention). The third is not a declaration, so it fails.
Declarations can be: methods, fields, constructors, inner classes
Post 1.8 you can use lambda expression too.
public class TestCompare {
public static void main() {
List<String> list = Arrays.asList("10", "1", "20", "11", "21", "12");
Comparator<String> cmp = (o1, o2) -> {
return Integer.valueOf(o1).compareTo(Integer.valueOf(o2));
};
Collections.sort(list, cmp);
}
}
