#7 Type Alias (Advanced Types)

 When we need a same values of type for different constants, instead of repeating the code, we can simply do as example;

type Employee={name: string, id: number}
let user: Employee={name:"Ram",id:10}

Here, we use *type* to create  an object type that can be used for other constants without repeating the code.

Comments

Post a Comment

Popular posts from this blog

#6 Objects (Fundamentals of TS)

 In object in TS, it can be written as, let User:{name: string , id: number}={name: "", id:10} User.name="Ram"; Like in JS, we can modify the object. But we need to specify an empty variable inside the object prior. we can modify as given above.  OR, let User:{name?:string , id: number}={id:10} User.name="Hari" In this approach, we specify the type of the variable *if* it exists and do not have to specify an empty variable. The first approach is preferable. ________________________________________________________________________________ If we want to make a variable read only, So we dont accidently modify it, We can say as, let User:{readonly name: string , id: number}={name: "", id:10} User.name="Ram";(CANNOT BE DONE) By using readonly to a variable in an object, we then cannot modify that variable later on.
Read more

#8 Union Type (Advanced Types)

 When we need a value that may be of either types like string or number, then we may use union type. It can be written as; function( weight: number | string ){      if(typeof weight === "number"){          return weight * 2;}      else{          return parseInt(weight)*2;} Here, the weight may either be number or a string. To make the weight act as a number, we use IF where if the (type of weight === number) so that the weight can act as a number ELSE it shall act as a string.
Read more