Q
Which PHP keyword is used to check if a function exists before calling it?

Answer & Solution

Answer: Option B
Solution:
The function_exists() function in PHP is used to check if a function exists before calling it, helping to avoid errors and ensuring code reliability.
Related Questions on Average

Which PHP keyword is used to declare a variable-length argument list in a function?

A). vararg

B). args

C). params

D). ...$args

What will be the output of the following PHP code?

<?php
function outer() {
function inner() {
echo 'Inner function';
}
}
inner();
?>

A). Inner function

B). Function does not exist: inner

C). Undefined function: inner

D). Function inner() { echo 'Inner function'; }

How do you define parameters in a PHP function?

A). Parameters are defined within parentheses after the function name

B). Parameters are defined using the keyword 'param'

C). Parameters are defined using curly braces {}

D). Parameters are defined using square brackets []

What is the output of the following PHP code?

<?php
function multiply(...$args) {
$result = 1;
foreach ($args as $value) {
$result *= $value;
}
return $result;
}
echo multiply(2, 3, 4);
?>

A). 24

B). 9

C). 6

D). 2

Which of the following statements about variable scope in PHP functions is true?

A). Variables defined inside a function have global scope

B). Variables defined outside a function have local scope

C). Variables defined inside a function have local scope

D). Variables defined outside a function have global scope

What is the significance of passing functions as arguments in PHP?

A). It allows functions to be called multiple times

B). It simplifies the function definition process

C). It enables dynamic function invocation and behavior

D). It prevents code duplication

Which of the following statements is true about function names in PHP?

A). Function names are case-sensitive

B). Function names must start with a dollar sign ($)

C). Function names cannot contain numbers

D). Function names can contain spaces

Which PHP feature allows defining functions without specifying their names?

A). Anonymous functions

B). Dynamic functions

C). Global functions

D). Static functions

What is the significance of default parameter values in PHP functions?

A). Default parameter values are required for all parameters in a function

B). Default parameter values allow specifying multiple default values for a parameter

C). Default parameter values allow parameters to be optional

D). Default parameter values allow specifying the data type of parameters

What will be the output of the following PHP code?

<?php
$greet = function($name) {
return 'Hello, $name!';
};
echo $greet('John');
?>

A). Hello, John!

B). Hello, $name!

C). function($name) {
return 'Hello, $name!';
}

D). John