TypeScript

1) install Node.js and npm

sudo apt update
sudo apt install nodejs npm

• sudo apt update: Updates your local package index.
• sudo apt install nodejs npm: Installs Node.js and npm.

verify Node.js and npm insstallation (Optional)

• node -v
• npm -v

2) instalatiion: npm install -g typescript.

• npm install: The command to install an npm package.
• -g: The flag for a global installation.
• typescript: The name of the package.

verify TypeScript installation

• tsc -v.

03 - Create Configuration And Watch Filles

Compilation : tsc index.ts

watch: tsc -w index.ts

helpe: tsc -h

tsc --init: file tsconfig contian:

"target": "es2016": "rootDir": "./src": adress file compiler "outDir": "./dist": adres output

tsc tsc -w

04 - Statically vs Dynamically Typed Lang

Statically Typed Language Like [Rut, C, C++]

Variables Types Are Static, Once You Declare It You Cannot Change.\ Type Of A Variable Is Known At Compile Time "Do Type Checking At Compile-Time".\

Have Better Performance At Run-Time Due To Not Needing To Check Types Dynamically. Error Detected Earlier

Dynamically Typed Language Like [PHP, Python, JavaScript]

Variables Type Are Dynamic, You Can Always Change It.\ "Type Checking At Execution-Time".\ Error Can Be Detected After Execution

05 - Type Annotations And Any Data Type

Type Annotations || Signature

Indicate The Data Type Of Variables.\ Indicate The Data Type Of Functions Input/Output.\ Objects, etc.

Why We Use It? Is It Mandatory? What Happen If We Didnt Use It?

let theName = "Jone";
let theAge: number = 40;
let hire: boolean = true;
let all: any = "Web School";

theNalme = "Osama";
all = 100;

06 - Type Annotations With Multidimension

Type Annotations With Multidimension Arrays

```TypeScript let arrayOne: number[] = [1, 2, 3, 4, 5]; let arrayTwo: string[] = ["A", "B", "C"]; let arrayThree:(string | number)[] = [1, 2, 3, "A", "B", "C"]