namespaces in PHP OOPS

 <?php


// NOTE: Namespace declaration statement has to be the very first statement or after any declare call in the script
// No code may exist outside of namespace {}

namespace abc {
    class xyz {}
}

namespace def {
    class xyz
    {
        public function __construct()
        {
            echo "XYZ from DEF namespace";
        }
    }
}
//If there is no Name present for namespace then it will consider as "Global namespace" as shown below:
namespace {
    class xyz
    {
        public function __construct()
        {
            echo "XYZ from Global namespace";
        }
    }
    $obj = new xyz();
    echo "<br><br>";
    $objTwo = new def\xyz();    //First way for making Object of namespace def => class xyz
    echo "<br><br>";

    use def\xyz as defXyz;      //Second way for making Object of namespace def => class xyz
    $objThree = new defXyz();
}

//There can be subnamespaces in namespace as shown below:
//Here below, "defTwo" is namespace and "ghi","jkl" is subnamespaces
namespace defTwo\ghi\jkl {
}

//We can declare namespace as shown below, class "pqr" will be consider of namespace "defThree"
// namespace defThree;
// class pqr
// {
//     public function message()
//     {
//         echo "Hello this is the method 'message' and class 'pqr' and they both is considered of namespace 'defThree'";
//     }
// }
// $obj = new pqr();
// $obj->message();


Comments

Post a Comment

Popular posts from this blog

GROUP BY Clause and HAVING Clause in PHP

GROUP BY :  The GROUP BY clause is used in conjunction with the SELECT Statement and Aggregate functions to group rows together by common column values. SELECT with GROUP BY Syntax : SELECT columns FROM table_name WHERE condition GROUP BY column_name(s); (Here above "condition" is Optional in above query). In "personal" table, there are 6 columns named id, name, percentage, age, gender, city. In "personal" table, column name "id" is PRIMARY KEY and column name "city" is FOREIGN KEY. In "courses" table, there are 2 columns named course_id and course_name. In "courses" table, column name "course_id" is PRIMARY KEY. In "city" table, there are 2 columns named cid and cityname. In "city" table, column name "cid" is PRIMARY KEY. SELECT with GROUP BY with Two Tables Syntax : SELECT columns FROM table1 INNER JOIN table2 ON table1.column_name = table2.column_name WHERE condition GROUP B...
Read more

Method Overriding in Traits in PHP

Image
  <?php class Base {     public function abc ()     {         echo "ABC method from Base class." ;     } } //The trait method(Here, abc() Method) will get priority compared to Parent class Method(Here, abc() Method) trait Test {     public function abc ()     {         echo "ABC method from test trait." ;     } } class Child extends Base {     use Test ;     public function abc ()     {         echo "ABC method from Child class." ;     } } $obj = new Child (); $obj -> abc ();
Read more

Mysqli database Connection and Display Table Data from Database

  <?php $servername = "localhost" ; $username = "root" ; $password = "" ; $dbname = "heer" ; $conn = new mysqli ( $servername , $username , $password , $dbname ); if ( $conn -> connect_error ) {     die ( "Connection Failed : " . $conn -> connect_error ); } $sql = " SELECT * FROM student " ; $result = $conn -> query ( $sql ); if ( $result -> num_rows > 0 ) {     while ( $row = $result -> fetch_assoc ())     {         echo "<pre>" ;         echo "Id: { $row ["id"]} - Name: { $row ["name"]} - Age: { $row ["age"]} - Phone No: { $row ["phone"]} - City: { $row ["city"]}" ;         echo "</pre>" ;     } } else {     echo "No result fount" ; } $conn -> close (); //  OUTPUT: //Id: 0 - Name: Raj - Age: 25 - Phone No: 9854233621 - City: Ahmedabad // Id: 1 - Name: Amit - Age: 22 - Phone No: 8533...
Read more