Type Script Types,typescript number,typescript string,typescript null,typescript never,typescript undefined

Type Script Type Test Part 1

Action @ StackBlitz refereed from TypeScriptLang 

Base Types
Description
Any
The super set of all data types
Built-in types
Includes number, string, boolean, void, null,never, and undefined
User-defined types
Includes Arrays, Enums, Classes, Interfaces etc…,

output of the code : 


Any


Any Data type is a super set of all data types , it denotes dynamic type ,Defualt value : undefined

Declaration :

anydatatype: any;


Built-in types
number




Represents integer and floating type, Defualt value : undefined

Declaration :



numberdatatype: number;

string


Represents integer and floating type, Defualt value : undefined

Declaration :


stringdatatype: number;


boolean


Represents integer and boolean type true or false, Defualt value : undefined

Declaration :


booeandatatype: number;

null


Its is used when the object does not have any values, value : null

to check null :


if (this.anydatatype === null) {
    console.log('Any data type value is null');
  }

undefined


Something hasn't been initialized, value : undefined

To check undefined :


  if (this.anydatatype === undefined) {
    console.log('Any data type value undefined');
  }

void


Return type of functions that do not return a value, value : void

To declare :
public welcometovoid(): void {
    console.log('welcometovoid function called');
  }




never


never is the return type for a function expression or an arrow function expression that always throws an exception or one that never returns, value : never

To declare :
//A function returning 'never' cannot have a reachable end point, below function wont run because it reach's the end point                                       public welcometovoid(): never {
    console.log('never end point reached');
  }
// Function returning never must have unreachable end point
public errornever(): never {
     throw new Error ('cant reach the end point');
   }
// Function returning never must have unreachable end point
 infiniteLoopnever(): never {
  while (true) {
  }


Assign Values

// Assign values for declared variables and console it 
assignvalues(): void {
  this.anydatatype = new Date();
  this.booeandatatype = true;
  this.numberdatatype = 50;
  this.stringdatatype = 'welcome to type script data types';
console.log('anydatatype', [this.anydatatype]);
console.log('numberdatatype', [this.numberdatatype]);
console.log('stringdatatype', [this.stringdatatype]);
console.log('booeandatatype', [this.booeandatatype]);
}
Assign Null Values
// Assign null values for declared variables and console it
assignnullvalues(): void {
  this.anydatatype = null;
  this.booeandatatype = null;
  this.numberdatatype = null;
  this.stringdatatype = null;
console.log('anydatatype', [this.anydatatype]);
console.log('numberdatatype', [this.numberdatatype]);
console.log('stringdatatype', [this.stringdatatype]);
console.log('booeandatatype', [this.booeandatatype]);
}

Type Script Types,typescript number,typescript string,typescript null,typescript never,typescript undefined Type Script Types,typescript number,typescript string,typescript null,typescript never,typescript undefined Reviewed by interfacecreator on 3:39:00 PM Rating: 5

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