I would appreciate it if someone could explain the significance of the image display area

Please add a description for this image

The table presented below outlines different declaration types:

Declaration Type Namespace Type Value
Namespace X X
Class X X
Enum X X
Interface X
Type Alias X
Function X
Variable X

After reviewing the documentation, it seems that 'X' symbol indicates that a particular type can be generated. For example, Namespace only generates Namespace type while Value is capable of creating multiple types such as Namespace, Class, Enum, Function, and Variable. But why use the "X" symbol? It appears that "X" signifies the ability to create.

I have some queries:

  1. Is my interpretation correct?
  2. Does the usage of 'X' imply clarity or ambiguity in the document?
typescript

Answer №1

When looking at the table, you can analyze the data in the following manner:

The table is divided into four columns, each with a specific heading and rows of cells underneath. The first column on the left is labeled "Declaration Type", containing descriptions of various declaration entities recognized by TypeScript:

  • Namespace
  • Class
  • Enum
  • Interface
  • Type Alias
  • Function
  • Variable

The other columns indicate different categories within the type system:

  • Namespace
  • Type
  • Value

If there is an 'x' symbol in one of the category columns, it means that the entity to the left of the 'x' can be utilized in the program under that category.

For instance, an interface can be used in a situation where a type is expected, but cannot be used in scenarios where a value or namespace is required:

TS Playground

interface Coordinates {
  x: number;
  y: number;
}

const point1: Coordinates = { x: 2, y: 3 };
//            ^^^^^^^^^^^ Ok!

const point2 = Coordinates; /*
               ~~~~~~~~~~~ Error
'Coordinates' only refers to a type, but is being used as a value here.(2693) */

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