PHP String Manipulation

Question 1

Q: What are the two ways to define a string in PHP?

Answer 1

A: Single quotes (‘) and double quotes (“).

Question 2

Q: What is the difference between single and double quotes in PHP?

Answer 2

A: Double quotes parse variables and escape sequences, while single quotes do not.

Question 3

Q: How do you concatenate two strings in PHP?

Answer 3

A: Using the . operator, e.g., $str1 . $str2;.

Question 4

Q: How do you find the length of a string in PHP?

Answer 4

A: Use the strlen() function.

Question 5

Q: How do you access a character at a specific index in a string?

Answer 5

A: Use array-like syntax, e.g., $string[0];.

Question 6

Q: How do you convert a string to lowercase in PHP?

Answer 6

A: Use the strtolower() function.

Question 7

Q: How do you convert a string to uppercase in PHP?

Answer 7

A: Use the strtoupper() function.

Question 8

Q: How do you capitalise the first letter of a string?

Answer 8

A: Use the ucfirst() function.

Question 9

Q: How do you capitalise the first letter of each word in a string?

Answer 9

A: Use the ucwords() function.

Question 10

Q: How do you convert the case of a string to title case?

Answer 10

A: Use ucwords(strtolower($string));.

Question 11

Q: How do you find the position of the first occurrence of a substring?

Answer 11

A: Use the strpos() function.

Question 12

Q: What function finds the last occurrence of a substring?

Answer 12

A: strrpos().

Question 13

Q: How do you check if a string contains a substring?

Answer 13

A: Use strpos() and check if the result is not false.

Question 14

Q: How do you replace all occurrences of a substring in a string?

Answer 14

A: Use the str_replace() function.

Question 15

Q: How do you perform a case-insensitive string replacement?

Answer 15

A: Use the str_ireplace() function.

Question 16

Q: How do you extract a substring from a string?

Answer 16

A: Use the substr() function.

Question 17

Q: How do you get the first N characters of a string?

Answer 17

A: Use substr($string, 0, N);.

Question 18

Q: How do you get the last N characters of a string?

Answer 18

A: Use substr($string, -N);.

Question 19

Q: How do you remove a portion of a string?

Answer 19

A: Combine substr() and concatenation.

Question 20

Q: How do you pad a string to a specific length?

Answer 20

A: Use the str_pad() function.

Question 21

Q: How do you split a string into an array?

Answer 21

A: Use the explode() function.

Question 22

Q: How do you join an array into a string?

Answer 22

A: Use the implode() function.

Question 23

Q: How do you split a string into chunks of a specific size?

Answer 23

A: Use the str_split() function.

Question 24

Q: What function breaks a string into an array based on a regular expression?

Answer 24

A: preg_split().

Question 25

Q: How do you join array elements with a delimiter?

Answer 25

A: Use implode($delimiter, $array);.

Question 26

Q: How do you remove whitespace from the beginning and end of a string?

Answer 26

A: Use the trim() function.

Question 27

Q: How do you remove whitespace only from the beginning of a string?

Answer 27

A: Use the ltrim() function.

Question 28

Q: How do you remove whitespace only from the end of a string?

Answer 28

A: Use the rtrim() function.

Question 29

Q: How do you pad a string to the left?

Answer 29

A: Use str_pad($string, $length, $pad_string, STR_PAD_LEFT);.

Question 30

Q: How do you pad a string to the right?

Answer 30

A: Use str_pad($string, $length, $pad_string, STR_PAD_RIGHT);.

Question 31

Q: How do you encode a string for HTML output?

Answer 31

A: Use the htmlspecialchars() function.

Question 32

Q: How do you decode an HTML-encoded string?

Answer 32

A: Use the html_entity_decode() function.

Question 33

Q: How do you encode a string for use in a URL?

Answer 33

A: Use the urlencode() function.

Question 34

Q: How do you decode a URL-encoded string?

Answer 34

A: Use the urldecode() function.

Question 35

Q: How do you convert special characters to HTML entities?

Answer 35

A: Use the htmlentities() function.

Question 36

Q: How do you reverse a string in PHP?

Answer 36

A: Use the strrev() function.

Question 37

Q: How do you repeat a string multiple times?

Answer 37

A: Use the str_repeat() function.

Question 38

Q: How do you shuffle the characters of a string?

Answer 38

A: Use the str_shuffle() function.

Question 39

Q: How do you compare two strings for equality?

Answer 39

A: Use the strcmp() function.

Question 40

Q: How do you hash a string in PHP?

Answer 40

A: Use the hash() function, e.g., hash(‘sha256’, $string);.