How Can I Achieve Named String Formatting in C#?

Named String Formatting in C#

In programming languages like Python, you can format strings by name rather than position. For example, you could have a string like this:

print '%(language)s has %(#)03d quote types.' % \
      {'language': "Python", "#": 2}

This would print "Python has 002 quote types."

In C#, there is no built-in method for formatting strings by name. However, there are a few ways to achieve a similar result.

Using a Dictionary

One option is to use a dictionary to map variable names to their values. You can then pass the dictionary to a custom string formatting method that uses the variable names to format the string.

Here is an example:

public static string FormatStringByName(string format, Dictionary<string, object> values)
{
    // Create a regular expression to match variable names in the format string.
    var regex = new Regex(@"\{(.*?)\}");

    // Replace each variable name with its value from the dictionary.
    var formattedString = regex.Replace(format, match => values[match.Groups[1].Value].ToString());

    return formattedString;
}

You can use this method like this:

var values = new Dictionary<string, object>
{
    { "some_variable", "hello" },
    { "some_other_variable", "world" }
};

string formattedString = FormatStringByName("{some_variable}: {some_other_variable}", values);

Using String Interpolation

In C# 6.0 and later, you can use string interpolation to format strings by name. String interpolation is a feature that allows you to embed expressions directly into strings.

Here is an example:

string formattedString = $"{some_variable}: {some_other_variable}";

This would print "hello: world".

Extension Methods

Another option is to use extension methods to add named string formatting functionality to the string class. Here is an example of an extension method that you can use:

public static class StringExtensions
{
    public static string FormatByName(this string format, object values)
    {
        // Get the type of the values object.
        var type = values.GetType();

        // Get the properties of the values object.
        var properties = type.GetProperties();

        // Create a regular expression to match variable names in the format string.
        var regex = new Regex(@"\{(.*?)\}");

        // Replace each variable name with its value from the values object.
        var formattedString = regex.Replace(format, match =>
        {
            var property = properties.FirstOrDefault(p => p.Name == match.Groups[1].Value);
            if (property != null)
            {
                return property.GetValue(values).ToString();
            }
            else
            {
                return match.Groups[1].Value;
            }
        });

        return formattedString;
    }
}

You can use this extension method like this:

string formattedString = "{some_variable}: {some_other_variable}".FormatByName(new { some_variable = "hello", some_other_variable = "world" });

The above is the detailed content of How Can I Achieve Named String Formatting in C#?. For more information, please follow other related articles on the PHP Chinese website!