feat(): use enums when needed

content/typescript/use-enums-when-needed.md

@@ -0,0 +1,47 @@
+---
+title: define enums for variables with already known multiple possible values
+---
+
+# Problem
+
+When we're working with variables, sometimes you'd need to have variables with already known multiple possible values, that will always be the same in your application (think about having a ticket status variable, `CLOSED`, `OPEN`, `WAITING RESPONSE`)
+
+# Solution
+
+Typescript allows us to define enumerators, which are variables with multiple defined possible values. By using enumerables TS will be able to infer and autocomplete the possible values of a variable inside your code.
+
+We can create different enumerables as follows:
+```ts
+export enum TicketStatus {
+  CLOSED: 'closed',
+  OPEN: 'open',
+  WAITING_RESPONSE: 'waiting response',
+}
+```
+
+We can assign any value to our enumerable properties, in this previous example, if you had numeric values for your variable then it'd look like this:
+```ts
+export enum TicketStatus {
+  CLOSED: 0,
+  OPEN:1,
+  WAITING_RESPONSE: 2,
+}
+```
+
+So when you or someone else is working later on the code they can use the enum like this:
+```ts
+if(ticket.status === TicketStatus.OPEN){
+  // do something
+}
+```
+or
+```ts
+switch(ticket.status){
+  case TicketStatus.OPEN:
+    break;
+  case TicketStatus.CLOSED:
+    break;
+  case TicketStatus.WAITING_RESPONSE:
+    break;
+}
+```