Блог пользователя eatmore

Автор eatmore, история, 3 года назад, По-английски

Java 15 was released a few days ago. Here are some changes that may be useful for competitive programming.

  • Pattern matching for instanceof, first introduced in Java 14, is still a preview.
  • Text blocks, first introduced in Java 13, are now final:
String input = """
	3 3
	1 2
	1 3
	2 3""";
  • Records, first introduced in Java 14, are now final:
record Fraction(int num, int den) {
	Fraction {
		if (den == 0) {
			throw new IllegalArgumentException("zero denominator");
		}
		if (den < 0) {
			num = -num;
			den = -den;
		}
	}

	Fraction add(Fraction o) {
		return new Fraction(num * o.den + den * o.num, den * o.den);
	}

	// ...
}
  • Useful new methods: CharSequence.isEmpty() (also inherited by String), String.stripIndent() (useful for text blocks), String.formatted(), Math.absExact().

Previous posts: Java 8, 9, 10, 11, 12, 13 and 14.

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3 года назад, # |
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Who uses Java pft

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    3 года назад, # ^ |
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    3 billion devices run Java !!

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    3 года назад, # ^ |
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    Not sure why you're getting downvoted. It is probably a joke.

    But even taken seriously, it's not such a terrible comment. JVM is awesome and if you want to use it, Kotlin is a great alternative to Java. It's like Java 35 with nicer syntax.

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3 года назад, # |
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A new feature is added in the form of sealed classes. Here no interface or class can inherit the parent sealed class. Only those class/interface can use the class features which are permitted by the sealed parent class.

Previously, inheritance was revoked by final class. Now, sealed class provide partial revokation with allowing only few structures to inherit them.

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3 года назад, # |
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the feeling from looking away from java 8 for 2 minutes and coming back to find oracle has made java 15 must be what parents feel when their kid goes to university