The variable 'items' is assumed to have type 'any' since it lacks a type annotation and is referenced within its own initializer

As a beginner in the world of coding, I've encountered a frustrating issue that I can't seem to resolve.

The error message reads:

'items' implicitly has type 'any' because it does not have a type annotation and is referenced directly or indirectly in its own initializer.

export class Model 
{
    user;
    items;

   constructor()  
   {
       this.user = "User";
       this.items = [
       
         new TodoItems("Sports", false),
         new TodoItems("Breakfast", false),
         new TodoItems("Reading Books", false),
         new TodoItems("Cinema", false),
       ];
   }
}

Answer №1

The problem lies in the lack of type definition for the items field, causing TypeScript to default it to type any. This results in TypeScript struggling to infer the array type when directly assigning values to a non-typed field in the constructor.

To address this issue, there are two potential solutions. The first option is to initialize and assign values directly to the field upon declaration.

export class Model 
{
    user;
    items = [
         new TodoItems("Sports", false),
         new TodoItems("Breakfast", false),
         new TodoItems("Reading Books", false),
         new TodoItems("Cinema", false),
       ];

   constructor()  
   {
       this.user = "User";
   }
}

Alternatively, you can first assign the array to a local variable with the correct type before assigning it to the field.

export class Model
{
    user;
    items;

   constructor()  
   {
       this.user = "User";
       const items = [
         new TodoItems("Sports", false),
         new TodoItems("Breakfast", false),
         new TodoItems("Reading Books", false),
         new TodoItems("Cinema", false),
       ];
       this.items = items;
   }
}

In my view, it's advisable to assign values directly to fields during their definition if automatic type inference is desired, especially when dealing with constant values that don't require assignment in the constructor. Otherwise, explicitly defining types for fields at declaration can prevent such issues from occurring.

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