Elance PHP Test Answers 2015 ( Part - 2 )




Elance PHP Test Answers 2015 ( Part - 1 )


What is the default timeout of a PHP session cookie ?
15 minutes
Never
Until the browser is closed
Depends on the client browser
30 minutes


class A{} class_alias( 'A', 'B' ); var_dump(new B); outputs ...
NULL
bool(false)
object(A)#1 (0) { }
object(B)#1 (0) { }


What does the following PHP code do? preg_filter($pattern, $replace, $subject)
Performs a regular expression search and replace
None of these
Performs a regular expression search and replace using a callback
Returns array entries that match the pattern


Which function can be used to simplify searches in databases where you know the pronunciation but not the spelling
explode
strtolower
soundex
parse_str
preg_search


What is the output of the following code? $one='two'; $two='one'; echo $$$one;
does not output anything
generates an error
onetwo
two
one


PHP's echo and print functions are not exactly alike. Which will accept multiple parameters and concatenate them in its "without parentheses" form?
print
neither echo nor print
echo
both echo and print


Which of the following statements is NOT true for PHP constants?
Their value cannot change for the duration of the script.
They are case sensitive.
The scope of a constant is local.
A valid constant name starts with a letter or an underscore.


Which of those is not magic method?
__toString
__sleep
__clone
__toInt
__callStatic


How do single quotes interpret strings in PHP?
None of these
literally
literally except for variables which are expanded
escape sequences are interpreted


When passing an object to json_encode(), the default behavior can be modified by:
Defining the __toJson() function.
Implementing the JsonSerializable interface.
It's not possible to change the default behavior.
Defining the __toArray() function.


Which statement opens a file for writing, to append data at the end of its content ?
fopen("myFile", "w")
fopen("myFile", "wa")
fopen("myFile", "r+")
fopen("myFile", "a")


what will be the output: $array1 = array("a" => "green", "b" => "brown", "c" => "blue", "red"); $array2 = array("a" => "green", "yellow", "red"); $result = array_diff_assoc($array1, $array2); print_r($result);
Array ( [b] => brown [c] => blue [0] => red )
Array ( [c] => brown [b] => blue [0] => red )
Array ( [b] => brown [c] => blue [d] => red )
Array ( [b] => brown [c] => blue [a] => red )


What will the following code output: array_map("print_r", array( 'a', 'b' ) );
ab
Nothing
Array{ [0] => 'a', [1] => 'b' }
a


What does the use of the final keyword in a method declaration prevent?
All of these
Specific properties within a class from being modified.
Child classes from overriding the method.
Objects from being modified.


$a = array('a' => 0, 'b' => 0, 'c' => 1, 'd' => 2); $b = array_flip($a); var_dump($b); What does the 'var_dump' function show ?
array(3) { [0]=> string(1) "a" [1]=> string(1) "b" [2]=> string(1) "c" [3]=> string(1) "d" }
array(4) { 'd' => int 2 'c' => int 1 'b' => int 0 'a' => int 0}
array(3) { [0]=> string(1) "b" [1]=> string(1) "c" [2]=> string(1) "d" }


What does the glob() function return?
All system global variables
An array of all global variables into the user defined function
An array of filenames / directories matching a specified pattern


Given an array of images, $images = array("img12.png", "img10.png", "img2.png", "img1.png"), which function will sort $images into ("img1.png", "img2.png", "img10.png", "img12.png")?
arsort($images);
natsort($images);
usort($images);
ksort($images);
asort($images);


Which PHP function would you use to get information about the current session cookie?
session_set_cookie_params()
set_cookie()
get_cookie()
session_get_cookie_params()


What is the correct way to call an anonymous function?
callback($functionName, $var);
call_function($var);
$func($var);
anonymous($var);


Choose the correct output of: <?php $email = 'admin@domain.tld'; echo strstr($email, '@'); ?>
admin@domain.tld
@domain.tld
domain.tld
admin


Which mode parameter should be used with the fopen() function to open a file and point to the end for writing only?
c+
w
a+
a


What is the result of calling json_encode() on an empty array?
[] - An empty JavaScript array
{} - An empty JavaScript object
undefined
'' - An empty JavaScript string


Which type of error can NOT be caught with a custom error handler?
E_USER_ERROR
E_RECOVERABLE_ERROR
E_WARNING
E_NOTICE
E_ERROR


Which of the following code snippets will split a string into an array with 3 elements?
$array = str_split("a b c", 2);
All of them
$array = split(" ", "a b c");
$array = explode(" ", "a b c");
$array = sscanf("a b c", "%s %s %s");


What will be the output for the following code? $values = array(0, NULL, FALSE); foreach($values as $key => $value) { echo isset($values[$key]) ? "TRUE " : "FALSE "; }
TRUE FALSE FALSE
TRUE FALSE TRUE
fatal error when using isset on an array
TRUE TRUE TRUE
FALSE FALSE FALSE


What are Traits in PHP?
Traits allow multiple inheritance for classes.
Traits allow code reuse without direct inheritance.
Traits are class interfaces.
Traits are all of these things.


is_a( $a, $b ) will:
it is not a built-in php function
check if $a is of class "$b" or has this class as one of its parents
Check if $a is of type "$b"


Which PHP function will return a file's last access time?
fileaccesstime()
file_access_time()
filectime()
fileatime()


What is the value of $a in the following: <?php $a = array_pad( array( 0 ), 2, 1 ); ?>
array( 0, 2 )
array( 2 )
array( 0, 1 )
NULL


Sleep(3000); will sleep the page for?
300 seconds
3000 seconds
30 seconds
3 seconds


What is the output of the following code? <?php echo str_pad("abc", 6, "7"); ?>
abc777
abcde67
abcde6666666
abcde777777
777abc


use keyword is used only for namespace
false
true


What is the result of the following code : <?php echo (strpos('abcdef', 'a')) ? : -1; ?>
true
0
Syntax error
-1
1


What is the result of the following code ? <?php $a = 1; echo $a++; $a *= 2; echo ++$a; ?>
24
11
25
14
15


What will be the final structure of the following array? $animals = array( 'dog', 'cat', true => 'lion' );
array( 0 => 'dog', 1 => 'cat', true => 'lion' )
Syntax Error will be thrown, as all keys must be of the same type
array( 0 => 'dog', 1 => 'lion' ) - boolean true will be changed to integer 1
Syntax Error will be thrown, as array keys can't be boolean values
array( 0 => 'dog', 1 => 'cat' ) - element with boolean key will be ignored


Which of the following functions inserts one or more elements to the beginning of an array?
array_merge()
array_walk()
array_unshift()
array_push()
array_shift()


What does this display? <?php $x = array('a'=>1, 'b'=>2, 'c'=>3); echo key($x);
"a"
array( 0, 1, 2 )
array( 'a', 'b', 'c' )
0


Which function returns an item from the argument list?
func_get_arg()
None of these
func_num_args()
func_get_args()


<?php $x = 1; echo($x++ + ++$x + $x)*2; Which will the output be?
12
15
14
16
13


Which of the following superglobals doesn't contain data from the client?
$_POST
$_COOKIE
$_SESSION
$_SERVER
$_GET



Which function can be used to convert data into a binary string according to a specified format?
pack()
nex2bin()
encode_hex()
printf()


What does mt_srand( [int $a] ); do?
Subtracts a random integer from the passed argument and returns the result
Returns a random integer
Returns a random string of the length specified by the first argument
Initializes a random number generator
This function does not exist


Which of the following protocols is not supported by PHP streams?
imap
ftp
ssh
bz2


Which elements can be encapsulated by namespaces?
Only classes
Classes, functions and constants
Classes, functions, constants and variables


How do you call a static method defined by the called class from a parent class?
None of these. It is not supported in the language. Parent classes cannot access static methods defined by children.
parent::func();
static::someFunc();
$obj = new __CLASS__; $obj->func();
self::someFunc();


True or False? Within the eval() function, code must be opened and closed with PHP tags, i.e. <?php echo 'hi'; ?>
False, but you can still exit and enter PHP mode using tags
True, you MUST use PHP tags as everywhere
False. You can't use PHP tags with eval()


An object can be counted with count() and sizeof() if it:
None of the above
Has a public __count() method
Was cast to an object from an array
Implements ArrayAccess


Which function would you use to obtain the ASCII value of a character?
chr( );
ord( );
val( );
asc( );


Which of the following network transports doesn’t PHP support?
tcp
pdc
unix
udg


When adding ('+' function) two variables of type integer and type string, what type is the resulting value?
Integer
Depends on the content of the string
String


What is the time complexity of a call to array_key_exists()?
O(N^2)
O(N * log N)
O(1)
O(log N)
O(N)


What function allows you to print a backtrace?
debug_backtrace_print
debug_print_backtrace
backtrace_print
backtrace
print_backtrace


Which of the following is not a valid PHP variable type conversion?
array to object
string to object
reference to array
object to reference


Which function is used to read an entire file into an array ?
file_to_array
fwrite
file_get_contents
file
fgets


Which of the following is the predefined class in PHP?
__PHP_Incomplete_Class
Special_Iterator
None of them
ErrorFault
PHP_RpcClient


What data types cannot be used with PHP5 Type Hinting?
Strings, Interface
Integers, Array
Objects, Array
Integer, Strings


What does this code do? namespace Hello\World;
It creates two namespaces : "Hello" and "Hello\World"
It creates two namespaces : "Hello\World" and "World"
It creates one namespace : "World"
It creates two namespaces : "Hello" and "World"
It creates one namespace : "Hello\World"


What is the name of variable storage container in php
Storage
zval
Memcache
Memrise
var


$a = array('z','x','y'); $b = sort($a); The value of $b is?
array('x','y','z')
False
array('z','y','x')
True


Which function returns the size of a specified file on the FTP server?
ftp_file_size()
get_ftp_size()
ftp_amount()
ftp_size()


Is it possible to typehint function arguments using native types (String, Bool, Array, Int, Float, Binary...)?
Yes, using all types
Only Array is supported
All types except String


Is there a function to listen on E_ERROR (fatal) errors?
It's not possible
set_error_handler()
register_shutdown_function()


Which PHP extension allows you to simplify converting between different calendar formats?
date/time
calendar
All of these
Julian


What is the output of the following code: <?php $x = 0x22; echo <<<'END' $x END; ?>
18
$x
0x22
Syntax error
34


Which PHP function reads entire file into an array?
file
fopen
readfile
fgets
file_get_contents

 

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