I'm using visual studio code with Language Support for Java(TM) by Red Hat plugin. I've set the runtime in settings.json as
"java.configuration.runtimes": [
{
"name": "JavaSE-17",
"path": "path/to/jdk19",
"default": true
}
]
The following standalone java file
import java.util.Objects;
public class Edge {
public final int first;
public final int second;
public Edge(int first, int second) {
this.first = first;
this.second = second;
}
@Override
public boolean equals(Object other) {
return switch (other) {
case Edge e -> (first == e.first && second == e.second) || (first == e.second && second == e.first);
default -> false;
};
}
@Override
public int hashCode() {
if (first < second)
return Objects.hash(first, second);
else
return Objects.hash(second, first);
}
}
gives following errors: Cannot switch on a value of type Object. Only convertible int values, strings or enum variables are permitted
, Edge cannot be resolved to a variable
, Syntax error on token "e", delete this token
, e cannot be resolved to a variable
.
IntelliJ didn't show any errors so I don't think the code is incorrect. I've tested that sealed
keyword from java 17 works. Although pattern matching for switch is a preview feature, I've heard that for standalone files preview features are enabled by default. Also I've seen a video someone using this feature in vscode. How could I use the feature?