PHP Strings

2.

What is the output of the following code snippet? echo stristr('pHPzphpZpHPZfoo', 'Z');

ZphpZPHPZfoo
ZPHPZfoo
Zphpzphpzfoo
PhpZPHPZfoo

Correct Answer

A. ZphpZPHPZfoo

Explanation

stristr returns $haystack (parameter 1) from $needle onwards ($parameter 2) in a case insensitive fashion

strstr($haystack, $needle) is the case sensitive version of the function

Rate this question:

3.

What is the output of the following script? echo strlen('foo' . chr(0) . '1'), ', ', strlen(0x00);

5, 1
3, 0
3, 4
5, 0
4, 0

Correct Answer

A. 5, 0

Explanation

0x00 (the number) when converted to a string has no length

Unlike in C, a null character won't terminate the string

Therefore D is correct

Rate this question:

4.

What is the function of the ucfirst and lcfirst functions?

To make the string's first character uppercase or lowercase, respectively.
To make the string's first word uppercase or lowercase, respectively.

Correct Answer

A. To make the string's first character uppercase or lowercase, respectively.

Explanation

Not many other options I could throw in there ;)

This one is just for review I suppose.

Rate this question:

1

5.

What is the output of the following? echo strcmp('first', 'second'), ", "; echo strcmp('44', '054'), ", "; echo strcmp('0x80', 'a'), ", "; echo strcmp('a', 'A');

-1, 1, -1, 1
-1, 0, -1, 1
1, 0, 1, -1
-1, -1, -1, -1
-1, -1, 1, -1

Correct Answer

A. -1, 0, -1, 1

Explanation

strcmp Returns < 0 if str1 is less than str2 ; > 0 if str1 is greater than str2 , and 0 if they are equal.

//Order of precedence is: z > a, z > A, Z > 1 > 9 > 0

Rate this question:

0

6.

What is the output of: echo strspn('1800-555-5555789', '0123456789');

1
7
4
0

Correct Answer

A. 1

Explanation

strspn is a pretty FUCKING RETARDED function and only checks the INITIAL SEGMENT of parameter 1 against all characters in parameter 2

If it was 1-800-555-whatever as the first parameter, then it would only return 1, because the INITIAL SEGMENT (containing characters from JUST parameter 2) is 1 character long

Rate this question:

7.

What is the output of: echo strcspn('1-800-555-5555', '0');

2
3
5
0

Correct Answer

A. 3

Explanation

B) is correct because strcspn returns the INITIAL SEGMENT of param1 that does NOT contain characters from param2

params 3 and 4 are start and length, respectively, which you can change the output of the function with.

Rate this question:

8.

What is the output of the following? echo strncasecmp('hello world', 'HelloWorld', 5), ', '; echo strcmp(44, 054), ', '; echo strcasecmp('xyz', 'ABC'), ', '; echo strncmp('0', 'Z', 1), ', '; echo strcmp('bb', 'aaaa');

1, 1, 1, -1, 1
0, 0, -1, -1, 1
1, 1, -23, 1, -1
-1, 0, -1, 1, -1
0, 0, -23, -1, 1

Correct Answer

A. 0, 0, -23, -1, 1

Explanation

E) is correct because for the first one, strncasecmp compares str1 to str2 in a case-insensitive fashion, for the first 5 characters

For the second one, 054 (octal 44) is converted to decimal first, and then 44 == 44

For the third one, strcasecmp, xyz is converted to uppercase or ABC is converted to lowercase, and a is 23 positions away from x in ASCII

For the fourth one, 0 is compared to Z, for the first 1 characters, letters (even uppercase ones) take precedence over numbers

Finally, for the fourth one. Even though bb is shorter than aaaa, b is higher than a, so str1 is "greater"

Rate this question:

9.

What is the output of the following? echo substr("abcdef", -2), ', '; echo substr("abcdef", 4), ', '; echo substr("abcdef", -3, -1), ', '; echo substr("abcdef", 4, -2), ', '; echo substr("abcdef", 2, -1);

Cdef, ef, de, , cde
Ef, ef, de, e, cde
Ef, ef, de, , cdef
Ef, ef, de, , cde
Abcd, de, de, , cde

Correct Answer

A. Ef, ef, de, , cde

Explanation

string substr ( string $string , int $start [, int $length ] )

negative start starting $start positions from the end of the string

negative length means reading in characters $length positions before the end of the string

Rate this question:

10.

What is the output of the following? $text = 'This is a test'; echo substr_count($text, 'is'), ', ' echo substr_count($text, 'is', 3), ', '; echo substr_count($text, 'is', 3, 3), ', '; echo substr_count($text, 'is', 5, 10), ', '; $text2 = 'gcdgcdgcd'; echo substr_count($text2, 'gcdgcd');

2, 1, 0, WARNING, 1
2, 1, 0, , 1
2, 1, 0, WARNING, 2
2, 1, 0, , 2
2, 1, 1, WARNING, 1

Correct Answer

A. 2, 1, 0, WARNING, 2

Explanation

C is correct
In the first one, there's 2 counts of $needle in $haystack

In the second one, by setting the offset to 3, there's now only one $needle in $haystack

In the third one, by setting the offset to 3 and length to 3, there's now only one $needle in $haystack (would be 's i')

In the fourth one, the offset + length exceed the length of the string, throwing a WARNING

In the fifth one, overlapping $needle's are NOT counted

Rate this question:

11.

What is the output of the following? echo str_replace('@', ' [anti-spam] ', '[email protected]', $count); echo $count . ' values found.'; $phrase = "You should eat fruits, vegetables, and fiber every day."; $healthy = array("fruits", "vegetables", "fiber"); $yummy = array("pizza", "beer", "ice cream"); echo str_replace($healthy, $yummy, $phrase); $vowels = array("a", "e", "i", "o", "u", "A", "E", "I", "O", "U"); echo str_replace($vowels, "", "Hello World of pHP");

[email protected] 0 values replaced. You should eat pizza, beer, and ice cream every day. Hll Wrld f PHP
Email [anti-spam] example.com 1 values replaced. You should eat pizza, beer, and ice cream every day. Hll Wrld f PHP
Email [anti-spam] example.com 1 values replaced. You should eat pizza, beer, and ice cream every day. Hllo World of PHP
Email [anti-spam] example.com 1 values replaced. You should eat ice cream, beer, and pizza every day. Hll Wrld f PHP

Correct Answer

A. Email [anti-spam] example.com 1 values replaced. You should eat pizza, beer, and ice cream every day. Hll Wrld f PHP

Explanation

B) is correct

mixed str_replace ( mixed $search , mixed $replace , mixed $subject [, int &$count ] )

@ is replaced with [anti-spam]

The fourth (optional) parameter $count (passed by reference) tells you how many values were counted

If both $search and $replace are passed in as arrays, each corresponding value is replaced

In the last one, all vowels are replaced with "" or an empty string

Rate this question:

12.

What is the output of: $string = "This is\tan example\nstring"; $tok = strtok($string, " \n\t"); while ($tok !== false) { echo "Word=$tok[br /]"; //pretend like [br /] is a real line break $tok = strtok(" \n\t"); }

This is an example string
This is an example string

Correct Answer

A. This is an example string

Explanation

In the token " \n\t" you'll notice there's a space, which is a valid delimiter, as such, B is correct, being split up across spaces as well as line breaks and tabs

Rate this question:

13.

What is the output of the following? $haystack = "Hello World!'; $needle = 'lo'; echo strrchr($haystack, $needle);

3
4
Llo World!
Ld!

Correct Answer

A. Ld!

Explanation

D) is correct because strrchr returns the part of the string which contains the last occurance of $needle in $haystack, up until the end of $haystack

Also, if $needle contains more than one characters, only the first one is used (unlike strstr)

Rate this question:

PHP Strings

What is the output of the following code snippet? $str = 'asdfghyo off on off'; $replace_pairs = array('a' => 'q', 's' => 'w', 'd' => 'e', 'f' => 'r', 'y' => 'z', 'o' => 'i', 'off' => 'on', 'on' => 'off'); echo strtr($str, $replace_pairs);

Quiz Preview

What is the output of the following code snippet? echo stristr('pHPzphpZpHPZfoo', 'Z');

What is the output of the following script? echo strlen('foo' . chr(0) . '1'), ', ', strlen(0x00);

What is the function of the ucfirst and lcfirst functions?

What is the output of the following? echo strcmp('first', 'second'), ", "; echo strcmp('44', '054'), ", "; echo strcmp('0x80', 'a'), ", "; echo strcmp('a', 'A');

What is the output of: echo strspn('1800-555-5555789', '0123456789');

What is the output of: echo strcspn('1-800-555-5555', '0');

What is the output of the following? echo strncasecmp('hello world', 'HelloWorld', 5), ', '; echo strcmp(44, 054), ', '; echo strcasecmp('xyz', 'ABC'), ', '; echo strncmp('0', 'Z', 1), ', '; echo strcmp('bb', 'aaaa');

What is the output of the following? echo substr("abcdef", -2), ', '; echo substr("abcdef", 4), ', '; echo substr("abcdef", -3, -1), ', '; echo substr("abcdef", 4, -2), ', '; echo substr("abcdef", 2, -1);

What is the output of the following? $text = 'This is a test'; echo substr_count($text, 'is'), ', ' echo substr_count($text, 'is', 3), ', '; echo substr_count($text, 'is', 3, 3), ', '; echo substr_count($text, 'is', 5, 10), ', '; $text2 = 'gcdgcdgcd'; echo substr_count($text2, 'gcdgcd');

What is the output of: $string = "This is\tan example\nstring"; $tok = strtok($string, " \n\t"); while ($tok !== false) { echo "Word=$tok[br /]"; //pretend like [br /] is a real line break $tok = strtok(" \n\t"); }

What is the output of the following? $haystack = "Hello World!'; $needle = 'lo'; echo strrchr($haystack, $needle);