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]);
}