Web Technology Experts Notes

Saturday, 20 June 2015

New features of PHP 5.5 with Examples

Following are 5.5 new features.

Generators: has been added via the yield keyword.

Generators provide an easy way to implement simple iterators.
For Example:

 function xrange($start, $limit, $step = 1) {
    for ($i = $start; $i <= $limit; $i += $step) {
        yield $i;
    }
  }
  
  echo 'List of odd Numbers:';
  
  foreach (xrange(1, 9, 2) as $number) {
      echo "$number ";
  }

finally: keyword added in try catch.

In try catch, finally block will be called every time, regardless of whether an exception has been thrown or not.
For Example:

    
    try {
    //write code here 
  }
  catch (Exception $e) {
      //Exception comes here
  }
  finally {
      echo "I am called everytime";
  }

New password hashing API
Password hashing API that makes it easier to securely hash and manage passwords using the same crypt() in PHP has been added.

foreach now supports list()

Now in PHP5.5, You can use list function inside foreach function.
See Example

 $listArray = [
    [10, 20],
    [30, 40],
    [50, 60],
];

foreach($listArray as list($a, $b)) {
    echo "A: $a; B: $b";
}

empty() supports expressions
Now you can use expression in empty function.
For Example:
```
  if(!empty(2*3)){
    echo "Its working";
    }
```

Array and String literal dereferencing.

String and Array can now be dereferenced directly to access individual elements OR characters.
For Example

echo 'Array dereferencing: ';
  echo [10, 02, 30][0];//10
  echo "\n";
  
  echo 'String dereferencing: ';
  echo 'Web Technology'[0]; //W

Class name resolution via ::class
ClassName::class to get a fully qualified name of class ClassName.
For Example
```
namespace Foo;
  class Bar {}
   
  echo Bar::class;
```
OPcache extension added
The Zend Optimiser+ opcode cache has been added to PHP5.5 as the new OPcache extension.
foreach now supports non-scalar keys. For non-scalar keys, an Iterator must be used as they cannot occur in native PHP array.
Apache 2.4 handler supported on Windows
Improvements to GD Library.

Friday, 19 June 2015

New features of PHP 5.4 with Examples

Following are 5.4 new features.

Traits has been added. For Example:

 //Create traits
trait HttpRequest 
{ 
      public function getHttpResponse($url, $port) 
      { 

            return $response; 
      } 
} 


//Use the traits

class ABC_API 
{ 
      use HttpRequest; // use our trait 

      public function getResponse($url) 
      { 
            return $this->getHttpResponse($url, 80); 
      } 
}

Short array syntax has been added. For Example:

$array = [1,2,3,'Web technology','Experts Notes'];

Function array dereferencing has been added. For Example:

function fruits(){
return array(0=>'Apple', 1=>'Banana', 2=>'Mango',3=>'Orange');
}   
echo fruits()[2]; //Mango

Closures now support $this.

Class member can access on instantiation has been added. For Example:

class test{
  function fruits(){
  return array(0=>'Apple', 1=>'Banana', 2=>'Mango',3=>'Orange');
  }
}
print_r((new test())->fruits());

Output:
Array
(
    [0] => Apple
    [1] => Banana
    [2] => Mango
    [3] => Orange
)

Class::{expr}() syntax is now supported. For Example:

class test{
static  function newMethod(){
echo "called function";
}
}  

$method = 'newMethod';
// this works 
test::$method(); 

// and this works 
test::{'newMethod'}();