TypeScript Programming Language

ES6 -> let (if multiple ref. change), cons (if no change)
- Use ES6 and ts

# TS:
- all features can be written in compile in js and run.
- TS is not loosly types. It's strict.
Example:
let abc: String;
abc: 634
Error: type 634 is not assignable to type 'String'.
Example:
let abc: any; // (data type can be used in abc variable. dont use any all time).

Important:
- npm i typescript g //(to install typescript)
- tsc - h //(help typescript)
- tsc abc.ts //(to run typescript. it now creates abc.js file . equivalent file code)
- tsc -v //(check version)
- ng --version (angular cli info-> angular cli version, node, os)
- overall angular application, we use angular cli. angular cli use webpack (like task runner, module bundler).
-ng equivalent to angular 2, 4, 5, 6

# Task runner -> small task like minify, file concatenate.
# Web pack -> modules bundle and make file

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Javascript: Object to Array and Array to Object

Output: Final Array [ { mango: 1 }, { apple: 2 }, { banana: 3 }, { orange: 1 }, { watermelon: 1 }, { papaya: 1 } ] Output: Final Object { mango: 1, apple: 2, banana: 3, orange: 1, watermelon: 1, papaya: 1 }

Javascript: Functions (inbuilt function)

FUNCTIONS A function is basic building block. In functional programming language, everything is done using functions. but pure function needed. a function is of two type: pure function and impure function. In pure function, it wont effect immutable and mutable function otherwise it will be impure function Example 1: function hi(){ console.log('I am inside hi'); } hi() Example 2: IIFE (immediately invoke functional expression) ()() Example 3: (function(){ console.log('I am anonymous function'); })(); Example 4: function sendMail(option){ //mail send function console.log('Option is', option); var sinuna = option.email; var to = option.to; var santoo = option.sub; var text = option.msg; option.email = 'info@fascinating.com' return true; return '...

Javascript: Promise

Source: https://www.geeksforgeeks.org/javascript-promises/ Promise is easier than callback because code is readable in promise. Promise has also a method. Methods: then, catch, finally (these methods use callback) Benefits of Promises Improves Code Readability Better handling of asynchronous operations Better flow of control definition in asynchronous logic Better Error Handling A Promise has four states: fulfilled : Action related to the promise succeeded rejected : Action related to the promise failed pending : Promise is still pending i.e not fulfilled or rejected yet settled : Promise has fulfilled or rejected

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