PHP Questions & Answers - Strings and Regular Expressions - 2

This set of PHP Questions and Answers for focuses on “Strings and Regular Expressions – 2”.

1. How many functions does PHP offer for searching and modifying strings using Perl-compatible regular expressions.
a) 7
b) 8
c) 9
d) 10
View Answer

Answer: b
Explanation: The functions are preg_filter(), preg_grep(), preg_match(), preg_match_all(), preg_quote(), preg_replace(), preg_replace_callback(), and preg_split().

2. What will be the output of the following PHP code?

```
    <?php
```

    $foods = array("pasta", "steak", "fish", "potatoes");

```
    $food = preg_grep("/^s/", $foods);
```
```
    print_r($food);
```
```
    ?>
```

a) Array ( [0] => pasta [1] => steak [2] => fish [3] => potatoes )
b) Array ( [3] => potatoes )
c) Array ( [1] => steak )
d) Array ( [0] => potatoes )
View Answer

Answer: c
Explanation: This function is used to search an array for foods beginning with s.

3. Say we have two compare two strings which of the following function/functions can you use?

i) strcmp() 
ii) strcasecmp()
iii) strspn() 
iv) strcspn()

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a) i) and ii)
b) iii) and iv)
c) only i)
d) i), ii), iii) and iv)
View Answer

Answer: d
Explanation: All of the functions mentioned above can be used to compare strings in some or the other way.

4. Which one of the following functions will convert a string to all uppercase?
a) strtoupper()
b) uppercase()
c) str_uppercase()
d) struppercase()
View Answer

Answer: a
Explanation: Its prototype follows string strtoupper(string str).

5. What will be the output of the following PHP code?

```
    <?php
```

    $title = "O'malley wins the heavyweight championship!";

```
    echo ucwords($title);
```
```
    ?>
```

a) O’Malley Wins The Heavyweight Championship!
b) O’malley Wins The Heavyweight Championship!
c) O’Malley wins the heavyweight championship!
d) o’malley wins the heavyweight championship!
View Answer

Answer: a
Explanation: The ucwords() function capitalizes the first letter of each word in a string. Its prototype follows: string ucwords(string str).

6. What will be the output of the following PHP code?

```
    <?php
```

    echo str_pad("Salad", 5)." is good.";

```
    ?>
```

a) SaladSaladSaladSaladSalad is good
b) is good SaladSaladSaladSaladSalad
c) is good Salad
d) Salad is good
View Answer

Answer: d
Explanation: The str_pad() function pads a string with a specified number of characters.

7. Which one of the following functions can be used to concatenate array elements to form a single delimited string?
a) explode()
b) implode()
c) concat()
d) concatenate()
View Answer

Answer: b
Explanation: None.

8. Which one of the following functions finds the last occurrence of a string, returning its numerical position?
a) strlastpos()
b) strpos()
c) strlast()
d) strrpos()
View Answer

Answer: d
Explanation: None.

9. What will be the output of the following PHP code?

```
    <?php
```
```
    $author = "[email protected]";
```

    $author = str_replace("a","@",$author);

    echo "Contact the author of this article at $author.";

```
    ?>
```

a) Contact the author of this article at nachiketh@[email protected]
b) Cont@ct the @uthor of this @rticle @t n@chiketh@[email protected]
c) Contact the author of this article at n@chiketh@[email protected]
d) Error
View Answer

Answer: c
Explanation: The str_replace() function case sensitively replaces all instances of a string with another.

10. What will be the output of the following PHP code?