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PHP
Articles by Alok Prasad
28 articles
How to call parent constructor in child class in PHP?
We will face two cases while calling the parent constructor method in child class.Case1We can't run directly the parent class constructor in child class if the child class defines a constructor. In order to run a parent constructor, a call to parent::__construct() within the child constructor is required.ExampleOutput: I am in Tutorials Point I am not in Tutorials PointExplanationIn the above example, we have used parent::__construct() to call the parent class constructor.Case2If the child does not define a constructor then it may be inherited from the parent class just like a normal class method(if it was not declared as private).ExampleOutputI ...
Read MoreWhat is PHP Output Buffering?
Output Buffering is a method to tell the PHP engine to hold the output data before sending it to the browser. As we know PHP sent the output data to the browser in pieces, but if we utilize the output buffering mechanism, the output data is stored in a variable and sent to the browser as one piece at the end of the script.ExampleLet's demonstrate with a simple example.Outputstring(5) "Hello" string(20) "HelloTutorials Point"ExplanationIn the above example ob_get_contents() grabs all of the data gathered since we called ob_start, i.e. everything in the buffer. After that send the output data at once.Advantages ...
Read MoreHow to validate an email address in PHP ?\\n
In this article, we will learn to validate an email with PHP regular expression. We will learn different methods to validate email address in PHP.Method1The function preg_match() checks the input matching with patterns using regular expressions.ExampleOutputValid email address.In the above example PHP preg_match() function has been used to search string for a pattern and PHP ternary operator has been used to return the true or false value based on the preg_match return.Method 2We will discuss email validation using filter_var() method.ExampleOutputpattrick@tutorialspoint.com is a valid email address
Read MoreWhat is dependency injection in PHP?\\n
Dependency injection is a procedure where one object supplies the dependencies of another object. Dependency Injection is a software design approach that allows avoiding hard-coding dependencies and makes it possible to change the dependencies both at runtime and compile time.There are numerous approaches to inject objects, here are couple generally known −Constructor InjectionIn this approach, we can inject an object through the class constructor.ExampleOutput3Setter Injectionwhere you inject the object to your class through a setter function.ExampleBenefits of Dependency InjectionAdding a new dependency is as easy as adding a new setter method, which does not interfere with the existing code.
Read MoreIs there any advantage to using __construct() instead of the class's name for a constructor in PHP?
Yes, there are several advantages to using the magic function __construct() instead of the class's name. Those are listed below −The magic function __construct is introduced in PHP 5.4. One advantage of using __construct() over ClassName() as a constructor is if you change the name of the class, you don't need to update the constructor which supports DRY(don't repeat yourself) concept.If you have a child class you can call parent::__construct()to call the parent constructor in an easy way.ExampleOutputThe class "myclass" was initiated! In SubClass constructorNote"__CLASS__" is what’s called a magic constant, which, in this case, returns the name of the ...
Read MoreProgram to find how many times a character appears in a string in PHP
ExampleOutputw appears 1 times e appears 2 times l appears 2 times c appears 1 times o appears 4 times m appears 1 times t appears 4 times u appears 1 times r appears 1 times i appears 2 times a appears 1 times s appears 1 times p appears 1 times n appears 1 times
Read MoreWhat is traits in PHP?
In 5.4 PHP version trait is introduced to PHP object-oriented programming. A trait is like class however it is only for grouping methods in a fine-grained and reliable way. It isn't permitted to instantiate a trait on its own. Traits are introduced to PHP 5.4 to overcome the problems of single inheritance. As we know in single inheritance class can only inherit from one other single class. In the case of trait, it enables a developer to reuse sets of methods freely in several independent classes living in different class hierarchies. Example Output Result of addition two numbers:8 ...
Read MoreWhat is the use of ini_set() in PHP?
PHP allows the user to modify some of its settings mentioned in php.ini using ini_set(). This function requires two string arguments. The first one is the name of the setting to be modified and the second one is the new value to be assigned to it.Parametersvar nameNot all the available options can be changed using ini_set(). There is a list of all available options in the appendix.new valueThe new value for the option.ExampleGiven the line of code will enable the display_error setting for the script if it’s disabled. We need to put the above statement, at the top of the ...
Read MoreIs PHP compiled or interpreted?
Basically, PHP is interpreted but PHP is compiled down to an intermediate bytecode that is then interpreted by the runtime Zend engine.PHP compiler is responsible forconvert the code to a bytecode that can be used by the runtime engine.resolve functions, names and classes namescreating a symbol tablePHP Interpreter doesGoes through the bytecode line by line and executes itHandles runtime exception
Read MoreDifferentiate between exception and error in PHP
Let's discuss the differences between errors and exceptions.Recovering from Error is not possible. The only solution to errors is to terminate the execution. Whereas we can recover from Exception by using either try-catch blocks or throwing an exception back to the caller.You will not be able to handle the Errors using try-catch blocks. Even if you handle them using try-catch blocks, your application will not recover if they happen. On the other hand, Exceptions can be handled using try-catch blocks and can make program flow normally if they happen.Exceptions are related to the application whereas Errors are related to the ...
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