Can I store a function in a variable in PHP?

PHP supports the concept of variable functions. This means that if a variable name has parentheses appended to it, PHP will look for a function with the same name as whatever the variable evaluates to, and will attempt to execute it.

How do you call a variable inside a function in PHP?

If you wish to use a PHP global variable inside a certain function, you should use the keyword global in front of the variable. In the example below you can see how PHP variables $x and $y are used inside a function called learnTest() .

Is include a function in PHP?

The Include() function is used to put data of one PHP file into another PHP file. If errors occur then the include() function produces a warning but does not stop the execution of the script i.e. the script will continue to execute.

Can PHP variable contain?

A variable name must start with a letter or the underscore character _ . A variable name cannot start with a number. A variable name in PHP can only contain alpha-numeric characters and underscores ( A-z , 0-9 , and _ ). A variable name cannot contain spaces.

How do you call a function in a variable?

There are two methods to call a function from string stored in a variable. The first one is by using the window object method and the second one is by using eval() method. The eval() method is older and it is deprecated.

What is a variable function?

Definition: A function is a mathematical relationship in which the values of a single dependent variable are determined by the values of one or more independent variables. Function means the dependent variable is determined by the independent variable(s).

Can we use variable number of arguments for a function in PHP?

PHP supports variable length argument function. It means you can pass 0, 1 or n number of arguments in function. To do so, 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.

How do you use the include function?

The include (or require ) statement takes all the text/code/markup that exists in the specified file and copies it into the file that uses the include statement. Including files is very useful when you want to include the same PHP, HTML, or text on multiple pages of a website.

What is the difference between include () and require ()?

include() Vs require() The only difference is that the include() statement generates a PHP alert but allows script execution to proceed if the file to be included cannot be found. At the same time, the require() statement generates a fatal error and terminates the script.

What are include () and require () functions?

What is variable function PHP?

If name of a variable has parentheses (with or without parameters in it) in front of it, PHP parser tries to find a function whose name corresponds to value of the variable and executes it. Such a function is called variable function. This feature is useful in implementing callbacks, function tables etc.