PHP 7 Interview Questions

PHP7 is the latest release in the PHP Programming language that has widened several programming avenues for PHP coders. It is considered to be the most sought-after programing language that has completely revamped the way web applications are created and developed. Released in December 2015, it offers faster performance, reduced memory consumption, anonymous class options, etc. After PHP5, it is the most important version to date.

PHP7 is a breakthrough in the programming world with its features outshining the features of all other versions to date. It offers myriad benefits to PHP coders such as-

• Double speed- Coders have been working really hard to scale up the speed and reduce the memory consumption and they have finally succeeded in doing so. PHP7 brings 50% better performance as compared with PHP5 and also reduces the consumption of resources.
• Supports error handling– Handling errors have always been a tedious task for PHP coders. But with the latest update in PHP7, engine exceptions will allow coders to handle and replace these errors with exceptions. However, PHP will continue to send errors like PHP5 if the exceptions are not caught.
• 64-bit windows support system– PHP7 supports 64-bit architecture machines.
• Anonymous classes– In PHP7, anonymous classes have been supported via a new class. This can be used in place of new class definitions.
• New spaceship and null coalescing operators– This feature in PHP7 allows comparison of two expressions. Comparisons are performed according to PHP’S type comparison rules. It aids the sorting process.

PHP7 has opened gates for coders to make programming language a better experience for them. As compared with PHP5, several upgrades have been made in PHP7. These are-

• Scalar type declarations– PHP7 has added scalar type hints such as int, strings, Boolean, etc in its long list of features. Earlier type hints were not available in previous versions, classes, arrays. This new addition to PHP has allowed coders to write correct and better PHP programs and ensures input consistency of the function.
• Return type declarations– To stimulate this function, we put the colon before opening the curly brace. It ensures output consistency and works the same as type hints. Return type declarations ensure the type of value returned from a function.
• Spaceship operators– it is the feature added to PHP7 that compares two expressions. It returns less than, greater than, or more than values.
• Closure:: call() function– it temporarily binds the object scope to a closure and invokes it. Closure are anonymous functions that act as callbacks for later executions. Call methods in PHP7 have aided the process for coders.

Scalar type declarations is the new feature in PHP7 that has added new declaration types such as int, string, Boolean, float. This declaration has two options-

• Coercive– this is a default mode in scalar type declarations, which need not be specified.
• Strict– it has to be explicitly hinted.

Scalar declarations have attracted a lot of controversy regarding its implementation. These are the statements that accept the arguments (parameters) and returns the values of the given scalar data type which can be int, float, string, etc. To stimulate this function, the name of the scalar data type should be added before the parameter.

FUNCTION: FunctionName (int $a, int $b)
{return $a +$b; }

The null coalescing operator is a new feature added to PHP7. It strictly checks for null or non-existent variables or indexes. This function is used to replace the ternary operation in conjunction with isset() function and it also returns its first operand if it exists and is not null. Otherwise, it returns the second operand.

There are few functions that have been deprecated in PHP7. They are-

• PHP4 style constructors are deprecated. The methods that have the same name as that of their class will be disapproved.
• Password()hash functions have been disapproved in PHP7.
• Capture_session_meta SS has been deprecated.
• Ldap_sort() is also deprecated.

In PHP7, Anonymous classes are those classes that don’t have any name. These anonymous classes are defined using the new class. It can replace full-class definition. When simple, one-off objects are created then anonymous classes are useful. They are internally generated names so we don’t have to give names to these classes. Objects created by same anonymous class are instances of that class.