Archives

• A Stupid Little TypeScript Mistake (Part 2)

  Thursday, August 19, 2021

  English TypeScript

  5 Comments

  After my blog post in June, here is another tale from a C# developer getting his feet wet with TypeScript.

  TypeScript’s type checking makes my life so much easier, but it does not catch everything. Recently I forgot an important part of a for-loop. Here is a stripped-down example:

  var items=["item0", "item1", "item2"];
  for (var n=0;items.length;n++)
  {
      // ...
  }

  The code compiles, but runs into an endless loop – the “n<” is missing in the condition.

  If I write similar code in C#…

  var items=new[] {"item0", "item1", "item2"};
  for (var n=0;items.Length;n++)
  {
      // ...
  }

  … the compiler tells me what I did wrong:

  Cannot implicitly convert type 'int' to 'bool'

  Ok, another (TypeScript) lesson learned.