All functions in JavaScript are called First class citizens
Higher order functions - functions that take in functions as arguments or return functions
// Tutorials
// console.log('Hello World');
// // variables
// // let name = "Vinit";
// console.log(name);
// let firstName = "Vinit";
// let lastName = "Jahagirdar";
// console.log(firstName + " " + lastName)
// const interestRate = 0.3;
// // interestRate = 1;
// console.log(interestRate)
// Primitive data types
// let name = "Vinit"; //String literal
// let age = 23; // Number literal
// let isApproved = false; // Boolean literal
// let firstName = undefined;
// let selectColor = null;
// Referenece types:
// Object
// Array
// Function
//object
let person = {
name: 'Mosh',
age: 30
};
console.log(person)
console.log(typeof (person))
console.log(person)
let selection = 'name';
person[selection] = 'Mary'
console.log(person.name)
// Arrays
let selectedColors = ['red', 'blue'];
console.log(selectedColors);
selectedColors[2] = 'green';
console.log(selectedColors.)
console.log(selectedColors[0]);
// Function
function greet(name, lastname) {
console.log("Hello" + ' ' + name + ' ' + lastname);
}
greet('John', 'Altman');
greet('Mary', 'Newman');
function square(number) {
return number * number;
}
console.log(square(29));
console.log(100);
console.log(false);
console.log('Hello')
const x = 100
console.log(x)
console.error('Alert');
console.warn('Warning');
console.table({name: 'Brad', email: '[email protected]'})
const styles = 'padding: 10 px; background-color: white; color: green;'
console.log('%cHello World!', styles)
// Multi word Formating for variable names
//firstName = camelCase
// first_name = underscore
// FirstName = PascalCase
// firstname = lowercase
// Re-assigning Variables
age = 31;
console.log(age);
let score;
score = 31;
console.log(score);
if (true){
score = score + 1;
}
console.log(score);
const x = 100;
const arr = [1, 2, 3, 4]
arr.push(5)
console.log(arr);
const person = {
name: "Vinit",
};
console.log(person.name);
person.name = "Bin";
console.log(person.name);
person.email = '[email protected]';
console.log(person);
// Primitive data types:
// - String: Sequence of characters. Must be in quotes or backticks
// - Number: Integers as well as floating-point numbers
// - Boolean: Logical entity / true or false
// - Null: Intentional absence of any object value
// - Undefined: A Variable that has not yet been defined / assigned
// - Symbol: Built-in object whise constructor returns a unique symbol
// - BigInt: Numbers that are greater than the "Number" tyoe can handle
// String
const firstName = 'Sara';
// Boolean
const hasKids = true;
//Null
const aptNumber = null;
//Undefined
// let score;
const score = undefined;
// Symbol
const id = Symbol('id');
// BigInt
const n = 90023290290293290n;
const output = n;
console.log(output, typeof output);
// Reference types or Objects
// Arrays (Object)
const numbers = [1, 2, 3, 4];
const person = {
name: 'Brad',
};
// Function aslo an object
function sayHello(){
console.log('Hello');
}
const output = sayHello;
console.log(output, typeof output);
The Modern JavaScript Tutorial
**alert**shows a message.
**prompt**shows a message asking the user to input text. It returns the text or, if Cancel button or Esc is clicked, null.
**confirm**shows a message and waits for the user to press “OK” or “Cancel”. It returns true for OK and false for Cancel/Esc.
There are 8 basic data types in JavaScript.
number for numbers of any kind: integer or floating-point, integers are limited by ±(2531).bigint for integer numbers of arbitrary length.string for strings. A string may have zero or more characters, there’s no separate single-character type.boolean for true/false.null for unknown values – a standalone type that has a single value null.undefined for unassigned values – a standalone type that has a single value undefined.symbol for unique identifiers.object for more complex data structures.The typeof operator allows us to see which type is stored in a variable.
typeof x, but typeof(x) is also possible."string".