Date type is not allowed in JSON. If we need to have a date, we have to include it as a string and then we can convert it back to date object later

var text = '{"name":"John", "birth":"1986-12-14", "city":"New York"}';

var obj = JSON.parse(text);
obj.birth = new Date(obj.birth);

document.write(obj.name + ", " + obj.birth)

Also we can use the second parameter of the

JSON.parse()

function, called

reviver

that checks each property, before returning the value

var text = '{ "name":"John", "birth":"1986-12-14", "city":"New York"}';

var obj = JSON.parse(text, function (key, value) {
  if (key == "birth") {
    return new Date(value);
  } else {
    return value;
  }
});

document.write(obj.name + ", " + obj.birth)

Solution to the problem was to add labels for the inputs but hidden by

CSS

/* Fix to pass Lighthouse: */
.label-hidden {
    position: absolute;
    height: 1px;
    width: 1px;
    clip: rect(1px,1px,1px,1px);
    border: 0;
    overflow: hidden
}

Another solution to the problem:

/* Fix to pass Lighthouse: */
label-hidden { 
    position: absolute; 
    top:-1000px; 
    left:-1000px; 
}

The password

123

will be encrypted and then decrypted back with

AES-128-ECB

encryption algorithm. Encrypts the text using the secret key

sec key

function encrypt_text($text, $secret_key)
{
    return openssl_encrypt($text,"AES-128-ECB", $secret_key);
}

Decrypts encrypted text (first parameter) using the secret key (second parameter)

function decrypt_text($encrypted_string, $secret_key)
{
    return openssl_decrypt($encrypted_string,"AES-128-ECB", $secret_key);
}

Calls the above two functions to perform encryption and decryption

// Secret key, that is used to encrypt and decrypt the 
$text
 content
$secret = 'sec key';

// the text that we want to encryption and decryption
$text = '123';

$password_encrypted = encrypt_text($text, $secret);
$password_decrypted = decrypt_text($password_encrypted, $secret);

echo 'Encrypted text: ' . $password_encrypted . '<br>';
echo 'Decrypted password: ' . $password_decrypted;

HTTP

stands for Hypertext Transfer Protocol. The standard (default) port for

HTTP

connection is

80

, but other port can also be used HTTP does not have any

security

...

HTTPS

stands for Hypertext Transfer Protocol Secure. HTTPS has a secure transfer. The standard port in

HTTPS

to transfer the information is

443

HTTPS protocol uses HTTP on connection encrypted by SSL or TLS (therefore it's secure)

margin & padding properties work only horizontally on inline elements (like

span

,

a

). Solution -

display: inline-block;

or

display: block;

multiple

attribute enables us to select several options at the same time.

size

attribute determines select tag height in options

List of all types of console notifications

console.log('console log');
console.info('console info');
console.warn('console warn');
console.error('console error');

REPLACE

statement updates the listed columns if primary key (one of the listed columns) already exists. Otherwise inserts as a new record

REPLACE INTO students (id, first_name, points)
VALUES (41, 'ილიკო', 147)

Similar to the

REPLACE INTO

statement is

ON DUPLICATE KEY

. The only difference is that on duplicate key it updates only the listed columns but omitted values stays the same

INSERT INTO students (id, first_name, points) 
VALUES (41, 'გიორგი', 149) 

ON DUPLICATE KEY 

UPDATE first_name = 'გიორგი', points = 123

Note 1

: If primary key is not listed, it will insert the record, but if the primary key is one of the listed columns, it will update the specified row that matches the primary key.

Note 2

: If the primary key exists, all the other omitted columns will get the default values after updating the record.

Variable described using keyword

let

uses block scope

let myNumber = 1

function callMePlease() {
  let myNumber = 2
  
  if (1 == 1) {
    let myNumber = 3    
    document.write('My number is: ' + myNumber + '</br>')
  }  
  document.write('My number is: ' + myNumber + '</br>')
}

document.write('My number is: ' + myNumber + '</br>')

callMePlease()

element.

childNodes

returns an array of an element's child nodes. element.

firstChild

returns the first child node of an element. element.

lastChild

returns the last child node of an element. element.

hasChildNodes

returns true if an element has any child nodes, otherwise false. element.

nextSibling

returns the next node at the same tree level. element.

previousSibling

returns the previous node at the same tree level. element.

parentNode

returns the parent node of an element.