Senior PHP Developer

Program :
function pypart($n)
{

for ($i = 0; $i < $n; $i++)
{

for($j = 0; $j <= $i; $j++ )
{

echo "* ";
}

echo "\n";
}
}
$n = 5;
pypart($n);
?>

sort() function can be used to sort an array in ascending order. 

Program :




$numbers = array(40, 61, 2, 22, 13);
sort($numbers);

$arrlength = count($numbers);
for($x = 0; $x < $arrlength; $x++) {
echo $numbers[$x];
echo "";
}
?>


 

retrieve image


// database connection
$conn = mysqli_connect("localhost", "root", "", "student");
// Fetch image from database
$img = mysqli_query($conn, "SELECT * FROM student_table");
while ($row = mysqli_fetch_array($img)) { 

echo ""; 

} 

 

There are mainly three types of design patterns: 
1. Creational : These design patterns are all about class instantiation or object creation. These patterns can be further categorized into Class-creational patterns and object-creational patterns. While class-creation patterns use inheritance effectively in the instantiation process, object-creation patterns use delegation effectively to get the job done. Creational design patterns are the Factory Method, Abstract Factory, Builder, Singleton, Object Pool, and Prototype. 
Use case of creational design pattern- 
1) Suppose a developer wants to create a simple DBConnection class to connect to a database and wants to access the database at multiple locations from code, generally what the developer will do is create an instance of DBConnection class and use it for doing database operations wherever required. This results in creating multiple connections from the database as each instance of DBConnection class will have a separate connection to the database. In order to deal with it, we create DBConnection class as a singleton class, so that only one instance of DBConnection is created and a single connection is established. Because we can manage DB Connection via one instance, we can control load balance, unnecessary connections, etc. 

2. Structural : These design patterns are about organizing different classes and objects to form larger structures and provide new functionality. Structural design patterns are Adapter, Bridge, Composite, Decorator, Facade, Flyweight, Private Class Data, and Proxy. 
Use Case Of Structural Design Pattern- 
1) When 2 interfaces are not compatible with each other and want to establish a relationship between them through an adapter it’s called an adapter design pattern. The adapter pattern converts the interface of a class into another interface or class that the client expects, i.e adapter lets classes work together that could not otherwise because of incompatibility. so in these types of incompatible scenarios, we can go for the adapter pattern.

3. Behavioral : Behavioral patterns are about identifying common communication patterns between objects and realizing these patterns. Behavioral patterns are Chain of responsibility, Command, Interpreter, Iterator, Mediator, Memento, Null Object, Observer, State, Strategy, Template method, Visitor