JuniorTheoryCommon

What does the program print?

JAVA

public class Main {
    public static void main(String[] args) {
        P a = new P(1, 2);
        P b = new P(1, 2);
        System.out.println(a.equals(b) + " " + a);
    }
}
record P(int x, int y) {}

true P[x=1, y=2]

Expecting false: a record's equals compares its components one by one, so two records with the same data are equal, even though == gives false.
Expecting the program not to compile: the compiler itself writes a record's constructor, accessors, equals, hashCode and toString.

What does a == b print for these two records, and why?
How do you get a point like a, but with x equal to 5?

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JuniorTheoryCommon

What does the program print?

JAVA

public class Main {
    public static void main(String[] args) {
        P a = new P(1, 2);
        P b = new P(1, 2);
        System.out.println(a.equals(b) + " " + a);
    }
}
record P(int x, int y) {}

true P[x=1, y=2]

Expecting false: a record's equals compares its components one by one, so two records with the same data are equal, even though == gives false.
Expecting the program not to compile: the compiler itself writes a record's constructor, accessors, equals, hashCode and toString.

What does a == b print for these two records, and why?
How do you get a point like a, but with x equal to 5?

Back to questions Open topic in roadmap →Answer it yourself — Quiz