Question

我想使用三元运算符来分解是否满足条件。

我知道此过程：structure(list(Period = c("2016-2017", "2017-2018", "2018-2019", "2019-2020", "2020-2021", "2021-2022", "2022-2023", "2023-2024", "2024-2025", "2025-2026", "2026-2027", "2027-2028", "2028-2029", "2029-2030", "2030-2031", "2016-2017", "2017-2018", "2018-2019", "2019-2020", "2020-2021", "2021-2022", "2022-2023", "2023-2024", "2024-2025", "2025-2026", "2026-2027", "2027-2028", "2028-2029", "2029-2030", "2030-2031", "2016-2017", "2017-2018", "2018-2019", "2019-2020", "2020-2021", "2021-2022", "2022-2023", "2023-2024", "2024-2025", "2025-2026", "2026-2027", "2027-2028", "2028-2029", "2029-2030", "2030-2031", "2016-2017", "2017-2018", "2018-2019", "2019-2020", "2020-2021", "2021-2022", "2022-2023", "2023-2024", "2024-2025", "2025-2026", "2026-2027", "2027-2028", "2028-2029", "2029-2030", "2030-2031", "2016-2017", "2017-2018", "2018-2019", "2019-2020", "2020-2021", "2021-2022", "2022-2023", "2023-2024", "2024-2025", "2025-2026", "2026-2027", "2027-2028", "2028-2029", "2029-2030", "2030-2031", "2016-2017", "2017-2018", "2018-2019", "2019-2020", "2020-2021", "2021-2022", "2022-2023", "2023-2024", "2024-2025", "2025-2026", "2026-2027", "2027-2028", "2028-2029", "2029-2030", "2030-2031", "2016-2017", "2017-2018", "2018-2019", "2019-2020", "2020-2021", "2021-2022", "2022-2023", "2023-2024", "2024-2025", "2025-2026", "2026-2027", "2027-2028", "2028-2029", "2029-2030", "2030-2031", "2016-2017", "2017-2018", "2018-2019", "2019-2020", "2020-2021", "2021-2022", "2022-2023", "2023-2024", "2024-2025", "2025-2026", "2026-2027", "2027-2028", "2028-2029", "2029-2030", "2030-2031"), City = c("Adelaide", "Adelaide", "Adelaide", "Adelaide", "Adelaide", "Adelaide", "Adelaide", "Adelaide", "Adelaide", "Adelaide", "Adelaide", "Adelaide", "Adelaide", "Adelaide", "Adelaide", "Brisbane", "Brisbane", "Brisbane", "Brisbane", "Brisbane", "Brisbane", "Brisbane", "Brisbane", "Brisbane", "Brisbane", "Brisbane", "Brisbane", "Brisbane", "Brisbane", "Brisbane", "Canberra", "Canberra", "Canberra", "Canberra", "Canberra", "Canberra", "Canberra", "Canberra", "Canberra", "Canberra", "Canberra", "Canberra", "Canberra", "Canberra", "Canberra", "Darwin", "Darwin", "Darwin", "Darwin", "Darwin", "Darwin", "Darwin", "Darwin", "Darwin", "Darwin", "Darwin", "Darwin", "Darwin", "Darwin", "Darwin", "Hobart", "Hobart", "Hobart", "Hobart", "Hobart", "Hobart", "Hobart", "Hobart", "Hobart", "Hobart", "Hobart", "Hobart", "Hobart", "Hobart", "Hobart", "Melbourne", "Melbourne", "Melbourne", "Melbourne", "Melbourne", "Melbourne", "Melbourne", "Melbourne", "Melbourne", "Melbourne", "Melbourne", "Melbourne", "Melbourne", "Melbourne", "Melbourne", "Perth", "Perth", "Perth", "Perth", "Perth", "Perth", "Perth", "Perth", "Perth", "Perth", "Perth", "Perth", "Perth", "Perth", "Perth", "Sydney", "Sydney", "Sydney", "Sydney", "Sydney", "Sydney", "Sydney", "Sydney", "Sydney", "Sydney", "Sydney", "Sydney", "Sydney", "Sydney", "Sydney"), `Growth_Rate` = c(2.51626610011951, 2.55164820931287, 2.57657088727502, 2.61958997722096, 2.64870864204937, 2.66803039158387, 2.68123985996072, 2.69161469161469, 2.71284349187497, 2.72003363906336, 2.71964386225247, 2.72484993399587, 2.72773561574085, 2.72847432024169, 2.7272309530374, 2.85954484097852, 2.87789660293085, 2.89473978672694, 2.90356257340467, 2.91463234206244, 2.92245132670665, 2.93225581163324, 2.9311130281383, 2.93051331067019, 2.92850281322904, 2.92517732387606, 2.92149192120694, 2.91156234267495, 2.89441500203832, 2.88034865293185, 2.88832690003993, 2.92367399741268, 2.92860734037205, 2.9551837831237, 2.95338631241846, 2.94930875576037, 2.96553267681289, 2.96706879686991, 2.98712265146717, 2.99272317310649, 2.99532291770325, 2.98550724637681, 2.96463082840792, 2.97949886104784, 2.97292514599186, 1.28352176525206, 1.27804141501294, 1.25658910601139, 1.2515118052269, 1.24642949883147, 1.24134393434214, 1.25652328114708, 1.24093069802352, 1.24054762022439, 1.23511033001367, 1.22968606838019, 1.22427591463415, 1.2282930961457, 1.24128312412831, 1.22606419617027, 1.76262396187406, 1.79407713498623, 1.82334833057068, 1.85382059800664, 1.88857720660187, 1.92400038415981, 1.94735850241849, 1.97177891428924, 1.99407819203577, 2.00545055986729, 2.02700740525628, 2.0465089801611, 2.05846256833649, 2.06613828915004, 2.05376747175066, 2.29848866498741, 2.34602099791389, 2.39917131687105, 2.4506444770762, 2.49394827366544, 2.54203051679667, 2.60023638512592, 2.62885836656328, 2.65649733774644, 2.67466636761243, 2.69783190431981, 2.72002127093858, 2.73859135971838, 2.73865611851553, 2.74167443229192, 2.5951334823608, 2.58959653384758, 2.6145545980519, 2.63834039111196, 2.65164684885149, 2.67572876916477, 2.68736805066854, 2.70698590825374, 2.71070520038367, 2.7284908035243, 2.73111734714043, 2.73353339489074, 2.73382642074712, 2.73033810261551, 2.72519205862002, 1.61106690334823, 1.67106420404573, 1.73128880883538, 1.78452864913977, 1.83220608599123, 1.88240318266616, 1.93255898606837, 1.9727515718166, 2.00674929960098, 2.03801379482538, 2.06867722925715, 2.09867047577189, 2.11814659726842, 2.13361181103117, 2.1471989794004)), row.names = c(NA, -120L), class = "data.frame")```

我具有以下if条件：

package theContest;

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Random;
import java.util.Scanner;

public class theContest {

    // The main() method
    public static void main(String[] args) throws FileNotFoundException {

        //
        String fileName = "contest.csv";
        File file = new File(fileName);
        if (!file.isFile()) {
            System.err.println("Cannot open file: " + fileName + ".");
            System.exit(0);
        }

        
        //
        int numContest = 0;
        Scanner input = new Scanner(file);
        while (input.hasNext()) {
            input.nextLine();
            numContest++;
        }
        input.close();
        System.out.println("Total of " + numContest + " contestants.");
        
        //
        int winner = 0;
        Random random = new Random();
        winner = random.nextInt(numContest) + 1;
        System.out.println("The winner is contestant number " + winner + ".");
        
        //
        String winnerDetails = "";
        input = new Scanner(file);
        for (int lineCount = 0; lineCount < winner; lineCount++) {
            winnerDetails = input.nextLine();
        }
        input.close();
        System.out.println("Winner is: " + winnerDetails);
        
        //
        String id = "";
        String name = "";
        String seats = "";
        String trans = "";
        String rate = "";
        String price = "";

        input = new Scanner(winnerDetails);
        input.useDelimiter(",");
        id = input.next();
        name = input.next();
        seats = input.next();
        trans = input.next();
        rate = input.next();
        price = input.next();
        input.close();
        System.out.println("Details are:");
        System.out.printf("%-5s : %s\n", "ID",  id);
        System.out.printf("%-5s : %s\n", "Name", name);
        System.out.printf("%-5s : %s\n", "Seating", seats};
        System.out.printf("%-5s : %s\n", "Transfer", trans};
        System.out.printf("%-5s : %s\n", "Rate", rate};
        System.out.printf("%-5s : %s\n", "Price", price};
    }
}

我想写：

condition ? consequent : alternative

作为替代我必须写些什么？

Answer 1

如果要检查多个字段，只需创建一个小的辅助方法即可根据条件（布尔值）返回字符串（或为空）：

➜ az acr repository delete --name MyRegistry --image Myrepository:Mytag
This operation will delete the manifest 'sha256:c88ac1f98fce390f5ae6c56b1d749721d9a51a5eb4396fbc25f11561817ed1b8' and all the following images: 'Myrepository:Mytag'.
Are you sure you want to continue? (y/n): y
➜

Answer 2

如果您只想在条件为真的情况下更改值（否则就不要更改），则不要添加任何内容作为“替代”部分：

messageErreur = !myField.IsNullOrNa() ? messageErreur + myField.IsDecimalWithMessage(nameof(myField)) : messageErreur;

使用C＃将if条件转换为三元

2 个答案: