How to incline the word "day" by numbers?

Question

How to incline the word "day" by numbers?

There is a value of the difference between two dates in days.
How to make formatting in this form:

1 day, 2 days, 3 days, 4 days, 5 days, 20 days, etc.?

That is, what would change the words день and дня.

1

java дата

Author: default locale, 2017-09-14

Source

2 answers

score 3 · Answer 1

As suggested by default locale:

public String getDayAddition(int num) {

    int preLastDigit = num % 100 / 10;

    if (preLastDigit == 1) {
        return "дней";
    }

    switch (num % 10) {
        case 1:
            return "день";
        case 2:
        case 3:
        case 4:
            return "дня";
        default:
            return "дней";
    }

}

Source

score 0 · Answer 2

I just wrote a universal decliner for different words, of course, if a word is added, then you need to describe three types of endings yourself: 0 array index - 1 unit, 101 units 1 array index - 2 units, 102 units 2 array index - 5 units, 11 units, 26 units, 10011 units. To do this, I attach three classes: util, enum, test with processing of two words: day and month

Utility:

public class WordDeclensionUtil {

/**
 * Получить слово в склонении в зависимости от переданного числа, например, для WordDeclensionEnum.MONTH
 * 11 месяцEВ
 * 21 месяц
 */
public static String getWordInDeclension(WordDeclensionEnum wordType, int n) {
    // смотрим две последние цифры
    int result = n % 100;
    if (result >=10 && result <= 20) {
        // если окончание 11 - 20
        return wordType.getDeclensions()[2];
    }

    // смотрим одну последнюю цифру
    result = n % 10;
    if (result == 0 || result > 4) {
        return wordType.getDeclensions()[2];
    }
    if (result > 1) {
        return wordType.getDeclensions()[1];
    } if (result == 1) {
        return wordType.getDeclensions()[0];
    }
    return null;
}
}

Enumeration:

@Getter
@AllArgsConstructor
public enum WordDeclensionEnum {
MONTH(new String[]{"месяц", "месяца", "месяцев"}),
DAY(new String[]{"день", "дня", "дней"}),
;

/**
 * Склонения в зависимо от переданного количества единиц сущности.
 * Минимальный размер: 3 склонения;
 * index
 * 0 - 1 единица, 101 единица
 * 1 - 2 единицы, 102 единицы
 * 2 - 5 единиц, 11 единиц, 26 единиц
 */
private String[] declensions;
}

Test to check the endings of words before running the project:

class WordDeclensionUtilTest {

@Test
void getWordInDeclension() {

    int countTestCases = 9;
    int[] count = {1, 2, 5, 10, 19, 1001, 1011, 10006, 202};

    @SuppressWarnings("unchecked")
    TwoFieldDto<WordDeclensionEnum, String[]>[] words = new TwoFieldDto[]{
            new TwoFieldDto<>(WordDeclensionEnum.MONTH, new String[]{"месяц", "месяца", "месяцев", "месяцев", "месяцев", "месяц", "месяцев", "месяцев", "месяца"}),
            new TwoFieldDto<>(WordDeclensionEnum.DAY, new String[]{"день", "дня", "дней", "дней", "дней", "день", "дней", "дней", "дня"}),
    };

    for (int i = 0; i < countTestCases; i++) {
        for (int j = 0; j < words.length; j++) {
            String wordInDeclension = WordDeclensionUtil.getWordInDeclension(words[j].getKey(), count[i]);
            assertEquals(words[j].getValue()[i], wordInDeclension, String.format("declension not equal: i = %s, j=%s", i, j));
        }
    }
}
}