Section 1.1: The Spread Operator

The spread operator allows for the inclusion of properties from other objects into a new object. For example:

const a = {

firstName: "james",

lastName: "smith",

};

const b = {

...a,

lastName: "White",

canSing: true,

};

In this case, the object b will be structured as follows:

{

"firstName": "james",

"lastName": "White",

"canSing": true

}

Section 1.2: Destructuring Nested Objects

Destructuring enables us to extract variables from nested objects. For instance:

const bob = {

name: "bob jones",

age: 29,

address: {

country: "Westeros",

state: "Crownlands",

pinCode: "500014",

},

};

const {

address: {

state,

pinCode

},

name

} = bob;

Here, state is 'Crownlands' and pinCode is '500014'.

Section 2.1: The Exponent Operator

You can use the exponent operator to perform exponentiation. For example, writing 2 ** 8 will yield 256.

Section 2.2: Promises with Finally

Utilizing finally allows you to execute code regardless of the promise's outcome. For instance:

Promise.resolve(1)

.then((result) => {})

.catch((error) => {})

.finally(() => {});

Section 2.3: Conditional Statements

You can implement conditionals using if-else. For example:

if ((age >= 15) && (age < 19)) {

status = "Eligible.";

} else {

status = "Not eligible.";

}

If age falls between 15 and 19, the first condition executes; otherwise, the second does.

Section 2.4: The Switch Statement

The switch statement is useful for evaluating multiple cases. For instance:

switch (new Date().getDay()) {

case 6:

text = "Saturday";

break;

case 0:

text = "Sunday";

break;

default:

text = "";

}

If getDay returns 6, then text is 'Saturday'; if it returns 0, then text is 'Sunday'.

Section 2.5: Variable Assignment

You can assign variables using let. For example:

let x; // uninitialized

let y = 1; // initialized

let a = 'hi'; // string assignment

let b = [1, 2, 3]; // array assignment

let c = false; // boolean assignment

const PI = 3.14; // constant assignment

You can also assign multiple variables in a single line:

let a = 1, b = 2, c = a + b;

Section 2.6: Strict Mode

By applying 'use strict', you can enforce better coding practices. For instance, this code will raise an error:

a = 1; // This will fail in strict mode

Section 2.7: JavaScript Values

JavaScript encompasses various value types such as booleans (false, true), numbers (1.2, 0n001, 0xF6, NaN), strings ('foo', 'bar'), and special values (null, undefined, Infinity).