What is "search: { ... }" / "break search" syntax officially called in Java?

Question

This code is from leetcode 681's solution:

class Solution {
    public String nextClosestTime(String time) {
        int cur = 60 * Integer.parseInt(time.substring(0, 2));
        cur += Integer.parseInt(time.substring(3));
        Set<Integer> allowed = new HashSet();
        for (char c: time.toCharArray()) if (c != ':') {
            allowed.add(c - '0');
        }

        while (true) {
            cur = (cur + 1) % (24 * 60);
            int[] digits = new int[]{cur / 60 / 10, cur / 60 % 10, cur % 60 / 10, cur % 60 % 10};
            search : {
                for (int d: digits) if (!allowed.contains(d)) break search;
                return String.format("%02d:%02d", cur / 60, cur % 60);
            }
        }
    }
}

Normally I will use Python to do leetcode but recently I want to practice with Java. And I notice this part:

            search : {
                for (int d: digits) if (!allowed.contains(d)) break search;
                return String.format("%02d:%02d", cur / 60, cur % 60);
            }

I have never seen such use before. I can understand what it is doing: feels like it customize a 'search' block and can break from it. And I just want to know what is the official name of such usage in Java. Thanks!

A [labeled branching statement](https://docs.oracle.com/javase/tutorial/java/nutsandbolts/branch.html) (or loop). — Elliott Frisch, Feb 26 '20 at 00:25
Does this answer your question? [How to use labels in java code?](https://stackoverflow.com/questions/28381212/how-to-use-labels-in-java-code) — mypetlion, Feb 26 '20 at 00:32
Always try to make your Stack Overflow question's title descriptive enough that someone can tell what your question is about without needing to click through to read the body. Hence, the edit to replace "this" with a description of what the "this" you're asking about is. — Charles Duffy, Feb 26 '20 at 00:43
@MadProgrammer, it does not transfer the flow of control to the label like "goto" does. — cowlinator, Feb 26 '20 at 00:43
@cowlinator But you could use `goto` to transfer control - it's just not used in the example — MadProgrammer, Feb 26 '20 at 00:53
@MadProgrammer There is a `goto` in Java, but [you cannot use it](https://stackoverflow.com/q/2545103/1270789) to transfer control! — Ken Y-N, Feb 26 '20 at 05:59
@KenY-N Honestly - personally I avoid labels and gotos in favour a more readable solutions ;) — MadProgrammer, Feb 26 '20 at 06:07

score 1 · Accepted Answer · answered Feb 26 '20 at 00:35

1

This construct is called the 'Labeled break' in Java.

More information can be found at

https://docs.oracle.com/javase/tutorial/java/nutsandbolts/branch.html

answered Feb 26 '20 at 00:35

Gopinath

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The break isn't labeled. A block is and the break has a label. (Though I accept you link mistakenly says that it is.) – Tom Hawtin - tackline Feb 26 '20 at 00:44

score 1 · Answer 2 · answered Feb 26 '20 at 00:44

1

What you have there is a labeled statement where the statement is a block and also a break statement with label. You don't have a labeled break statement - that is legal but weird.

answered Feb 26 '20 at 00:44

Tom Hawtin - tackline

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What is "search: { ... }" / "break search" syntax officially called in Java?

2 Answers2