PHP developers are still in high demand for the web application development. And there are more and more high-end enterprise level websites getting created using PHP. Hence, we are adding 15 more PHP interview questions and answers for the experienced web developers. In our last post, you might have seen that we’d published the 30 PHP questions for beginners.
Starting with our first post on the 50 most essential AngularJS interview questions, we later had taken up other web development topics like NodeJS, CSS/HTML, and now PHP. Our team has studied the latest trends and the patterns of the questions asked in the interviews. All of this help us serve you better and achieve our goal of making you succeed in job interviews.
PHP Interview Questions and Answers for Experienced
PHP Interview Questions and Answers
Q-1. What is the difference between unlink and unset function in PHP?
<unlink()> function is useful for file system handling. We use this function when we want to delete the files (physically). Let’s see a sample code.
$xx = fopen('sample.html', 'a');
fwrite($xx, '<h1>Hello !!</h1>');
unset() function performs variable management. It makes a variable undefined. Or we can say that unset() changes the value of a given variable to null. Thus, in PHP if a user wants to destroy a variable, it uses unset(). It can remove a single variable, multiple variables, or an element from an array. Let’s see a sample code.
$val = 200;
echo $val; //Out put will be 200
$val1 = unset($val);
echo $val1; //Output will be null
unset($val); // remove a single variable
unset($sample_array['element']); //remove a single element in an array
unset($val1, $val2, $val3); // remove multiple variables
Q-2. What are PHP Traits?
It is a mechanism that allows us to do code reusability in single inheritance language, such as PHP. Its structure is almost same as that of PHP class, just that it is a group of reusable functions. Despite having same name and definition, they appear in several classes, each one having a separate declaration leading to code duplicity. We can group these functions and create PHP Traits. The class can use this Trait to include the functionality of the functions defined in it.
Let’s take an example, where we create a Message class.
Let say there exists a class Welcome.
public function welcome()