有没有更清洁的方式来写这个？ （数字到字符串）

Question

我做了一个数字到数字转换器，但是看起来写起来太冗长了。 我似乎有些人在谈论使用开关。我应该用一个开关重写还是有更好的写方法？

import javafx.application.Application;
import javafx.beans.binding.Bindings;
import javafx.beans.binding.BooleanBinding;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.TextField;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class BooleanBindingExample extends Application {

    public static void main(String[] args) {
        launch(args);
    }

    @Override
    public void start(Stage primaryStage) {

        // Simple interface
        VBox root = new VBox(5);
        root.setPadding(new Insets(10));
        root.setAlignment(Pos.CENTER);

        // TextField and Button
        TextField textField = new TextField();
        Button button = new Button("Click Me");
        root.getChildren().addAll(textField, button);

        // Create a BooleanBinding for the textField to hold whether it is null
        BooleanBinding isTextFieldEmpty = Bindings.isEmpty(textField.textProperty());

        // Now, bind the Button's disableProperty to that BooleanBinding
        button.disableProperty().bind(isTextFieldEmpty);

        // Show the Stage
        primaryStage.setWidth(300);
        primaryStage.setHeight(300);
        primaryStage.setScene(new Scene(root));
        primaryStage.show();
    }
}

Answer 1

尝试使用数组文字。

string numberToString(int n) {
  return (n >= 0 && n <= 9) ?
    (string[]){
      "zero",
      "one",
      "two",
      "three",
      "four",
      "five",
      "six",
      "seven",
      "eight",
      "nine",
    }[n]
  :
    "?";
}

Answer 2

我根本不会使用开关

std::string numberToString(int n) 
{
    const char *literal[] = {"zero", "one", "two", "three", "four", "five",
                           "six", "seven", "eight", "nine"};
    const char *no_result = "?";

    return std::string ( (n < 0 || n >= 10) ? no_result : literal[n]); 
}

return语句中的转换是可选的（隐式发生），但我更希望使其明确。

如果需要，可以将literal的类型no_result和std::string设置为

。

Answer 3

简短版本：

std::string numberToString(int n)
{
    return (const char *[]){"zero", "one", "two", "three", "four", "five",
            "six", "seven", "eight", "nine", "?"}[unsigned(n) < 11 ? n : 10];
}

Answer 4

这很容易工作，并且可读性和可重用性。

#include <string>
#include <vector>
#include <iostream>

class Converter {
private:
    const std::vector<std::string> numbers{ "zero", "one", "two", "three", "four",
                                            "five", "six", "seven", "eight", "nine", "?" };
public:
    std::string operator()( int n ) { 
        if ((n < 0) || (n > 10))
             return numbers.at(10);   
       return numbers.at(n); 
    }
};


int main() {
     Converter c;
     for ( int i = -5; i < 15; i++ )
         std::cout << c(5) << '\n';

     return 0;
}

-输出-

?
?
?
?
?
zero
one
two
three
four
five
six
seven
eight
nine
?
?
?
?
?
?