34 Best PHP Programming interview questions by Devquora

This helps to prevent the PHP error of ‘maximum execution time exceeded.’ We can also specify this in the php.ini file. Because PHP is a server-side language and Javascript is a client-side language, these two cannot interact. Some of the most commonly used functions in PHP include strlen(), str_replace(), urlencode(), and md5(). PHP variables are values stored in memory that the user can manipulate. They store data for a specific purpose and can be used in calculations and other processes. PHP variables can be declared with keywords such as ‘var,’ ‘int,’ ‘float,’ and’ array.’ After announcing a variable, it can then be used to store a value.

SQL injections are a method to alter a query in a SQL statement send to the database server. That modified query then might leak information like username/password combinations and can help the intruder to further compromise the server. Getters and setters are methods used to declare or obtain the values of variables, usually private ones. They are important because it allows for a central location that is able to handle data prior to declaring it or returning it to the developer. Fatal– this type of error causes a termination of the script execution when it occurs.

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This is important for any PHP developer to know because it shows an understanding that building applications is more than just being able to write code. One must also have an understanding about privileges and accessibility of that code. All objects in PHP have Constructor and Destructor methods built-in. The Constructor method is called immediately after a new instance of the class is being created, and it’s used to initialize class properties. Then, include “error_reporting” in your code to display all types of error messages during the script execution.

The string function strstr returns part of allString from the first occurrence of occ to the end of allString. Stristr() is identical to strstr() except that it is case insensitive. The boolean function isset determines if a variable is set and is not NULL.

This is important for any developer who is looking to enter a team-based / application development job to know. Getters and setters are often used when dealing with objects, especially ones that will https://wizardsdev.com/ end up in a database or other storage medium. As such, getting an industry-standard Post Graduate Program in Full Stack Web Development course certification will steer you in the right direction.

How can we increase execution time of a PHP script?

Get free resources to help create great software and manage high-performing teams. This type of interview is similar to the standard ones, except that they are done remotely. It has become more common due to social distancing restrictions brought about by the COVID pandemic.

• For example, content may be changed on the fly based on user input, or the content may be generated with the help of a database.
• See next section for a complete list of all the SERVER variables.
• Once the Constants have been set, may not be redefined or undefined.
• _FILE_ – It represents the full path and filename of the file.
• What are the differences between PHP constants and variables?
• Here are essential PHP interview questions and answers to practice before your big day, for both experienced developers and junior candidates.

Use examples from your past experience to highlight your communication and teaching skills. I have been working as a senior PHP developer for over five years now and have extensive experience in all these areas. After creating your objects, you will be able to call member functions related to that object. One member function will be able to process member variable of related object only. Following example shows how to set title and prices for the three books by calling member functions. Once you defined your class, then you can create as many objects as you like of that class type.

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All PHP variables are denoted by a leading dollar sign ($). The PHP parsing engine needs a way to distinguish PHP code from other elements on the page. Escaping a string means reducing the ambiguity in quotes used in that string. Variable names are case sensitive, but function names are not. If you define the function name in lowercase and call them in upper case, it will still work.

If your change isn.t showing up, remember to stop and restart httpd. If it still isn.t showing up, use phpinfo() to check the path to php.ini. If the function require() cannot access to the file then it ends with a fatal error. However, the include() function gives a warning and the PHP script continues to execute.

What are some of the popular PHP frameworks?

This is useful when you want to retrieve value of a constant, but you do not know its name, i.e. It is stored in a variable or returned by a function. PHP does a good job of automatically converting types from one to another when necessary.

The GET method is restricted to send upto 1024 characters only. $$message is a variable whose name is stored in $message. For example, if $message contains “var”, $$message is the same as $var. Split() – The Middle PHP developer job split() function will divide a string into various elements, the boundaries of each element based on the occurrence of pattern in string. _FILE_ – It represents the full path and filename of the file.

PHP setcookie() function is used to set cookie with HTTP response. Once the cookie is set, you can access it by $_COOKIE superglobal variable. The header() function is used to send a raw HTTP header to a client. For example, you can’t print any HTML element before using this function.

Understanding the error types is very important as they help developers understand what is going on during the development, and what to look out for during debugging. PHP Magic Methods are powerful functions that perform specific tasks within a program. These functions are unique as they are part of the core language and can be used to create custom functions that allow for complex operations. If the function requires () fails to access the file, then it ends with a ‘fatal’ error.

The function asort() is a variant of the standard function sort() that preserves the index association. Please note that as of PHP 7.2, this code produces an error. The goto statement can be placed to enable jumping inside the PHP program.

An exception that is thrown at compile time is called a checked exception. This exception cannot be ignored and must be handled with care. To do this, you will need to write code in a try-catch block and handle the exception. On the other hand, an exception thrown at runtime is called an unchecked-exception. PHP callbacks are functions that can be called dynamically by PHP.

What is the difference between $ message and $ message in PHP?

It means you can pass 0, 1 or n number of arguments in function. To do this, you need to use 3 ellipses before the argument name. The 3 dot concept is implemented for variable length argument since PHP 5.6. The PHP count() function is used to count total elements in the array, or something an object.

Booleans − have only two possible values either true or false. PEAR is a framework and repository for reusable PHP components. PEAR means PHP Extension and Application Repository. It extends PHP and provides a higher level of programming for web developers. Given an array of numbers , Write a php function that will print numbers that are not duplicated in array.