Stringify key-value pairs in dictionary

Question

I have made a dictionary which contains two values: a DateTime and a string.

Now I want to print everything from the dictionary to a Textbox. Does anybody know how to do this?

I have used this code to print the dictionary to the console:

private void button1_Click(object sender, EventArgs e) { Dictionary<DateTime, string> dictionary = new Dictionary<DateTime, string>(); dictionary.Add(monthCalendar1.SelectionStart, textBox1.Text); foreach (KeyValuePair<DateTime, string> kvp in dictionary) { //textBox3.Text += ("Key = {0}, Value = {1}", kvp.Key, kvp.Value); Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value); } }

That gives the following error: Only assignement, call, increment, await and new object expressions can be used as a statement. — Barry The Wizard
– Barry The Wizard, Commented Feb 17, 2015 at 0:18
I think you're just missing a string.Format in the commented out line. — petelids
– petelids, Commented Feb 17, 2015 at 0:18

CheGueVerra · Accepted Answer · 2015-02-17 00:33:48Z

Just to close this

foreach (KeyValuePair<DateTime, string> kvp in dictionary) { //textBox3.Text += ("Key = {0}, Value = {1}", kvp.Key, kvp.Value); Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value); }

Changes to this

foreach (KeyValuePair<DateTime, string> kvp in dictionary) { //textBox3.Text += ("Key = {0}, Value = {1}", kvp.Key, kvp.Value); textBox3.Text += string.Format("Key = {0}, Value = {1}", kvp.Key, kvp.Value); }

ggorlen · Accepted Answer · 2021-08-31 22:24:26Z

98

Cleaner way using LINQ:

var lines = dictionary.Select(kvp => kvp.Key + ": " + kvp.Value.ToString()); textBox3.Text = string.Join(Environment.NewLine, lines);

kvp is short for "key-value pair".

edited Aug 31, 2021 at 22:24

ggorlen

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answered May 30, 2016 at 12:56

Sachin Gaur

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1 Comment

r.pedrosa Over a year ago

with $ - string interpolation kvp => $"{kvp.Key}:{kvp.Value}"

Erik Anderson · Accepted Answer · 2022-07-01 20:18:31Z

There's more than one way to stringify a dictionary; here's my solution:

Use Select() to convert the key-value pair to a string;
Convert to a list of strings;
Write out to the console using ForEach().

dict.Select(i => $"{i.Key}: {i.Value}").ToList().ForEach(Console.WriteLine);

Leo · Accepted Answer · 2021-02-15 17:01:44Z

There are so many ways to do this, here is some more:

string.Join(Environment.NewLine, dictionary.Select(a => $"{a.Key}: {a.Value}"))

dictionary.Select(a => $"{a.Key}: {a.Value}{Environment.NewLine}")).Aggregate((a,b)=>a+b)

new String(dictionary.SelectMany(a => $"{a.Key}: {a.Value} {Environment.NewLine}").ToArray())

Additionally, you can then use one of these and encapsulate it in an extension method:

public static class DictionaryExtensions { public static string ToReadable<T,V>(this Dictionary<T, V> d){ return string.Join(Environment.NewLine, d.Select(a => $"{a.Key}: {a.Value}")); } }

And use it like this: yourDictionary.ToReadable().

Isnt it kind of a shame that you cant print lists/collections just like that?
This is beautiful, thank you: string.Join(Environment.NewLine, dictionary.Select(a => $"{a.Key}: {a.Value}"))

SAR_H · Accepted Answer · 2020-11-02 08:46:29Z

6

My goto is

Console.WriteLine( Serialize(dictionary.ToList() ) );

Make sure you include the package using static System.Text.Json.JsonSerializer;

answered Nov 2, 2020 at 8:46

SAR_H

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1 Comment

marsnebulasoup Over a year ago

I also needed to add using System.Linq for the .ToList()

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