public function services() {
        $data = [
            'title' => 'langs',
            'languages' => ['PHP', 'Java', 'Python']
        ];
        return view('pages/services')->with($data);
}

Receive the passed array

@extends('layouts.app')

@section('cntnt')
    <h3>{{$title}}</h3>
    @if(count($languages))
        @foreach($languages as $language)
            <li>{{$language}}</li>
        @endforeach
    @endif
@endsection

In this example we are not able to call

who()

method of the child class

B

from parent class

A

class A {
    public static function who() {
        echo __CLASS__;
    }
    public static function test() {
        self::who();
    }
}

class B extends A {
    public static function who() {
        echo __CLASS__;
    }
}

B::test();

The code will call

who()

method of parent class and print its name

A

If we need

test()

to call

who()

method of child class

B

from parent class, then we can use

late static binding

technique. To achieve it, we use

static

keyword:

class A {
    public static function who() {
        echo __CLASS__;
    }
    public static function test() {
        static::who(); // Here comes Late Static Bindings
    }
}

class B extends A {
    public static function who() {
        echo __CLASS__;
    }
}

B::test();

Categorizes students based on their points

SELECT *, 
    IF(points>=90, "Brilliant", IF(points>=80, "Gold", IF(points>=60, "Silver", "Lazy"))) AS class
FROM `students`
ORDER BY points DESC

The same result using

UNION

keyword

SELECT *, 'Brilliant' AS class
FROM `students`
WHERE points >= 90
UNION
SELECT *, 'Gold'
FROM `students`
WHERE points >= 80 
    AND points < 90
UNION
SELECT *, 'Silver'
FROM `students`
WHERE points >= 60 
    AND points < 80
UNION
SELECT *, 'Lazy'
FROM `students`
WHERE points < 60
ORDER BY points DESC

The same result using

CASE WHEN

conditional statement

SELECT *, 
    CASE 
      	WHEN points>90 THEN "Brilliant"
      	WHEN points>80 THEN "Gold"
      	WHEN points>60 THEN "Silver"
      	ELSE "Lazy"
    END as 'class'
FROM `students`
ORDER BY points DESC

JSONP 

is a technique to get data from server without cross-domain issues. JSONP does not use the

XMLHttpRequest

, instead it uses

<script>

tag.

window.onload = function() {
  var s = document.createElement("script");
  s.src = "https://www.w3schools.com/js/demo_jsonp.php";
  document.write(s.outerHTML);
};

// This function will run after the content is fully loaded from the server
function myFunc(myObj) {
  document.write(myObj.name + " is " + myObj.age + " and he lives in " + myObj.city);
} 

Requesting a content from another domain can cause problems, due to cross-domain policy.

<script>

tag does not have this problem and that is the reason why it uses the tag instead of using

XMLHttpRequest

object. ... Content of the remote

demo_jsonp.php

file

myFunc({"name":"John", "age":30, "city":"New York"});

If we have a complex object, and we’d like to convert it into a string, to send it over a network, or just to output it for logging purposes, we can use

toString

method

let user = {
  name: "John",
  age: 30,
  toString() {
    return `{name1: "${this.name}", age1: ${this.age}}`;
  }
};

document.write(user);
// document.write(JSON.stringify(user));

The code above will produce the following result:

{name1: "John", age1: 30}

An interface can extend another interface in the same way that a class can extend another class

Interface IBar {
    public function method3();
}

Interface IArray {
    public function method2();
}

Interface IFoo extends IBar, IArray {
    public function method1();
}

class class1 implements IFoo {
    public function method1() {
        
    }
    public function method2() {
        
    }
    // public function method3() {
        
    // }
}

Class

class1

implements

IFoo

interface which extends other two interfaces itself. Because the class has not implemented

method3

method (commented), then the following error will be generated:

Fatal error:  Class class1 contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (IBar::method3)

.flex-container > div {
  flex:2;
}

The selector above has class name and tag name, therefore it's more specific than this selector:

.search {
  flex:4;
}

That's why the second selector has no effect in this example. With more specific selector, like this:

.flex-container .search {
  flex:4;
}

the .search item will be twice as wide as the other flex items.

The element is positioned relative to its first positioned (not static) ancestor element

.parent {
    position: relative;
}
.parent h1 {
    position: absolute;
    top: 10px;
}

https://youtu.be/aFtByxWjfLY?t=200

The

callback function

name is the same as the

callback

variable passed to the

URL

https://api.github.com/users/yui?callback=handleJSONP_variable

The content returned from the request:

handleJSONP_variable({"meta": {
  "Content-Type": "application/javascript; charset=utf-8",
  "Cache-Control": "public, max-age=60, s-maxage=60",
  "Vary": "Accept",
  "status": 200,
  ...
}, "data": {
  "login": "yui",
  "name": "YUI Library",
  "company": null,
  "blog": "http://yuilibrary.com/",
  "location": "Sunnyvale, CA",
  "email": null,
  "public_repos": 31,
  ...
}})

Selects all

h2

elements that has parent with both

cl1

and

cl2

classes

.cl1.cl2 h2{
    color: red;
}