Answer:- PHP magic constants are predefined constants, which change based on their use. They start with a double underscore (__) and end with a double underscore (__).

Answer:- PHP data types are used to hold different types of data or values. There are 8 primitive data types which are further categorized in 3 types: Scalar types Compound types Special types

Answer:- PHP single line comment is made in two ways: Using // (C++ style single line comment), Using # (Unix Shell style single line comment) PHP multi-line comment is made by enclosing all lines within.

Answer:- For, while, do-while and for each.

Answer:- The PHP count() function is used to count total elements in the array, or something an object.

Answer:- The header() function is used to send a raw HTTP header to a client. It must be called before sending the actual output. For example, you cant print any HTML element before using this function.

Answer:- The isset() function checks if the variable is defined and not null.

Answer:- PHP parameterized functions are functions with parameters. You can pass any number of parameters inside a function. These given parameters act as variables inside your function. They are specified inside the parentheses, after the function name. Output depends upon dynamic values passed as parameters into the function.

Answer:- PHP supports variable length argument function. It means you can pass 0, 1 or n number of arguments in function. To do this, you need to use 3 ellipses (dots) before the argument name. The 3 dot concept is implemented for variable length argument since PHP 5.6.

Answer:- PHP supports variable length argument function. It means you can pass 0, 1 or n number of arguments.

Answer:- An array is used to store multiple values in a single value. In PHP, it orders maps of pairs of keys and values. It saves the collection of the data type.

Answer:- There are three types of array in PHP: Indexed array: an array with a numeric key. Associative array: an array where each key has its specific value. Multidimensional array: an array containing one or more arrays within itself.

Answer:- There are many array functions in PHP: array(), array_change_key_case(), array_chunk(), count(), sort(), array_reverse(), array_search(), array_intersect()

Answer:- The indexed array holds elements in an indexed form which is represented by number starting from 0 and incremented by 1. For example: $season=array("summer","winter","spring","autumn"); The associative array holds elements with name. For example: $salary=array("Sonoo"=>"350000","John"=>"450000","Kartik"=>"200000");