The complete book on angular 11 - Chapter 2 TypeScript

 Chapter 2 TypeScript

1. 

npm install -g typescript

npm install -g tsun (TypeScript Upgraded Node)

tsun

> var fullName: string = 'Nate Murray'

> console.log(fullName)

var jobs: Array<string> = ['IBM', 'Microsoft', 'Google']; equals with the below

var jobs: string[] = ['Apple', 'Dell', 'HP'];

enum Role {Employee, Manager, Admin};

var role: Role = Role.Employee;

console.log('Roles: ', Role[0], ',', Role[1], 'and', Role[2]);

any is the default type if we omit typing for a given variable. Having a variable of

type any allows it to receive any kind of value.

var something: any = 'as string';

something = 1;

something = [1, 2, 3];

2. 

//ES5-like example

var data = ['Alice Green', 'Paul Pfifer', 'Louis Blakenship'];

data.forEach(function(line) { console.log(line); });

However with the fat arrow => syntax we can instead rewrite it like so:

// Typescript example

var data: string[] = ['Alice Green', 'Paul Pfifer', 'Louis Blakenship'];

data.forEach( (line) => console.log(line) );

Parentheses are optional when there’s only one parameter.

data.forEach( line => console.log(line) );

3.

var firstName = "Nate";

var lastName = "Murray";

// interpolate a string (enclose your string in backticks)

var greeting = `Hello ${firstName} ${lastName}`;

console.log(greeting);

TODO: page 121