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

What will be the output of the following PHP code?

<?php
function uppercase($str) {
return strtoupper($str);
}
echo uppercase('hello');
?>

A). HELLO

B). hello

C). Uppercase

D). Undefined function: uppercase

What is the syntax for calling a function in PHP?

A). callFunction()

B). function callFunction()

C). callFunction

D). callFunction;

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 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 PHP feature allows defining functions without specifying their names?

A). Anonymous functions

B). Dynamic functions

C). Global functions

D). Static functions

What is the purpose of parameters in PHP functions?

A). To store values within the function

B). To define the return type of the function

C). To specify values that are passed to the function when it is called

D). To specify the visibility of the function

What is the output of the following PHP code?

<?php
$num = 10;
function testScope() {
global $num;
echo $num;
}
testScope();
?>

A). 10

B). 0

C). Undefined variable: num

D). Variable $num cannot be accessed outside the function

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 PHP feature allows passing a function as an argument to another function?

A). Dynamic functions

B). Global functions

C). Static functions

D). Callbacks

What is the output of the following PHP code?

<?php
function greet() {
echo 'Hello, World!';
}
if (function_exists('greet')) {
greet();
} else {
echo 'Function does not exist';
}
?>

A). Hello, World!

B). Function does not exist

C). Undefined function: greet

D). Function greet() { echo 'Hello, World!'; }