Every December, developers tackle a daily coding challenge to practice JavaScript, TypeScript and Python. Each task is self-contained, includes ready-to-run tests and increases in difficulty so anyone can join at any level.
It’s a fun, practical way to learn new techniques, stay motivated and compare solutions with the community. If you want to build consistency and level up your coding this month, this challenge is perfect.
→ <a href="https://adventjs.dev" target="_blank" rel="noopener nofollow">https://adventjs.dev</a>

Miguel Ángel Durán

AdventJS offers daily coding challenges throughout December for JavaScript, TypeScript, and Python developers. Each challenge includes built-in tests, scales in difficulty to accommodate all skill levels, and provides opportunities to compare solutions with other developers. It's designed to help developers build consistent practice habits and improve their coding skills.

JavaScript, TypeScript and Python coding challenges every day of December

Es genial! 💪
Espero cada año para resolver estos code challenges
Gracias Midu! 🤩

I’ve done up to day 3! it’s an impressive and didactic work! thank you!!

Day 9 task was challenging but I could make it in the end. I submitted in Python but I did it in VBA before. It’s bee so long since I used “select - case” control :) . Here my solution:
<pre><code>Sub advJS2025_9()
&#x27;Day 9 of AdventJS -- &gt; https://adventjs.dev/challenges/2025/9
 Dim board() As Variant
 Dim wb As Workbook
 Dim sh As Worksheet
 Dim maxRow As Long
 Dim c As Long
 Dim i As Long
 Dim next_c As Long
 Dim next_i As Long
 Dim chr As String
 Dim d As Variant
 Dim directions As Variant
 Dim rs As String
 
 Set wb = ThisWorkbook
 Set sh = wb.Worksheets(&quot;AdvJs_9&quot;)
 maxRow = sh.Cells(sh.Rows.Count, 1).End(xlUp).Row
 Set rng = sh.Range(&quot;A1:A&quot; &amp; maxRow)
 board = rng.Value

 directions = Array(&quot;R&quot;, &quot;U&quot;)
 rs = &quot;fail&quot;
 
 Dim initial_i As Long
 Dim initial_c As Long
 
 For initial_i = LBound(board, 1) To UBound(board, 1)
 initial_c = InStr(1, board(initial_i, 1), &quot;@&quot;)
 If initial_c &lt;&gt; 0 Then
 i = initial_i
 c = initial_c
 Debug.Print &quot;Posición inicial de &#x27;@&#x27;: Fila = &quot; &amp; i &amp; &quot;, Columna = &quot; &amp; c
 Exit For
 End If
 Next initial_i
 
 If initial_c = 0 Then
 Debug.Print &quot;Robot not found&quot;
 Exit Sub
 End If
 
 For Each d In directions
 next_i = i
 next_c = c
 chr = &quot;&quot;
 
 Select Case d
 Case &quot;U&quot; &#x27; UP
 next_i = i - 1
 Case &quot;D&quot; &#x27; DOWN
 next_i = i + 1
 Case &quot;R&quot; &#x27; RIGHT
 next_c = c + 1
 Case &quot;L&quot; &#x27; LEFT
 next_c = c - 1
 Case Else
 rs = &quot;fail&quot;
 Exit For
 End Select
 
 Dim row_limit As Boolean
 Dim col_limit As Boolean
 
 row_limit = (next_i &lt; LBound(board, 1) Or next_i &gt; UBound(board, 1))
 col_limit = (next_c &lt; 1 Or next_c &gt; Len(board(i, 1)))
 
 If row_limit Or col_limit Then
 rs = &quot;crash&quot;
 Else
 chr = Mid(board(next_i, 1), next_c, 1)
 End If
 
 If rs = &quot;crash&quot; Then
 Debug.Print &quot;Movimiento &quot; &amp; d &amp; &quot;: CRASH (Límite)&quot;
 Exit For
 ElseIf chr = &quot;*&quot; Then
 rs = &quot;success&quot;
 Debug.Print &quot;Movimiento &quot; &amp; d &amp; &quot;: SUCCESS (Meta)&quot;
 Exit For
 ElseIf chr = &quot;#&quot; Then
 rs = &quot;crash&quot;
 Debug.Print &quot;Movimiento &quot; &amp; d &amp; &quot;: CRASH (Obstáculo)&quot;
 Exit For
 Else
 &#x27; Free path (chr = &quot;.&quot;)
 i = next_i
 c = next_c
 Debug.Print &quot;Movimiento &quot; &amp; d &amp; &quot;: Libre. Nueva posición: (&quot; &amp; i &amp; &quot;, &quot; &amp; c &amp; &quot;)&quot;
 End If
 Next d

 Debug.Print &quot;Resultado final: &quot; &amp; rs
End Sub


</code></pre>