PHP String Functions

PHP inbuilt supports a few data types. Apart from these, PHP also supports many functions that are used while working on some data. PHP String functions are some of those functions that are used to manipulate string data. All these functions are predefined. There is a need for installing any plugins. Let’s look at some of the PHP string functions.

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Below are some of the string functions, and examples are illustrated with the following syntax.

<?php
echo func( "<data>" );
?>

Examples of String Functions in PHP

The string function is easy to use. Here we will discuss how to use string function in PHP programming with the help of examples.

1. Addcslashes()

This returns a string with backslashes in front of specific characters

E.g.:

echo addcslashes ("Hello World!","W");

Output:

Hellow World

2. Addslashes()

This returns string with backslashes in front of predefined characters

E.g.:

echo addcslashes('Hello "World" you');

Output:

Hello ” World” you.

3. bin2hex()

Converts binary data into hexadecimal data

E.g.:

echo bin2hex ("Hello");

Output:

48656c6c6f

4. chop()

Removes whitespaces or any predefined characters from the right end if specified

E.g.:

echo chop ("WelcomeBack" , "Back");

Output:

Welcome

5. chr()

This PHP string function returns the character of a specified ASCII value.

E.g.:

echo char(52);

Output:

4

6. chunk_split()

Used to split a string into smaller parts

E.g.:

echo chunk_split ($str, 2,", ");

Output:

We,lc,om,e,

7. convert_uudecode()

This decodes a uuencoded string

E.g.:

echo convert_uudecode ("+22!L;W9E( %!( 4\"$`\n` ");

Output:

I love PHP!

convert_uuencode() does the reverse of convert_uudecode()

8. count_chars()

This PHP string function outputs the data about the number of characters in a string.

E.g.:

echo count_chars ("Hello", 3);

Output:

Helo

Note: The integer value is the mode which is used to specify the type of output required

• 0 – an array with the byte-value as key and the frequency of every byte as value.
• 1 – same as 0, but only byte-values with a frequency greater than zero are listed.
• 2 – same as 0, but only byte-values with a frequency equal to zero are listed.
• 3 – a string containing all unique characters is returned.
• 4 – a string containing all not used characters is returned.

9. crc32()

This calculates the 32-bit cyclic redundancy checksum( A Mathematical function) of a string.

E.g.:

crc32 ("Hello World!");

Output:

472456355

10. Implode()

This joins the array elements with a specified string

E.g.:

$array = array ('lastname', 'email', 'phone');
echo implode(",", $array);

Output:

lastname, email, phone

Note: join() also does the same. It is the alias of implode().

11. htmlspecialchars()

This converts some predefined characters to HTML entities, i.e. it shows the source.

Eg:

$str = "I am <b>Bold</b>";
echo $str; => I am <strong>Bold</strong>
echo htmlspecialchars($str);

Output:

I am Bold

12. ltrim()

This PHP string function removes white spaces or predefined characters from the left of the string.

E.g.:

echo ltrim ("Just a sample", "Just");

Output:

a sample

Note: rtrim() does a similar job from right
trim() does the same from both ends.

13. number_format()

This formats the number with grouped thousands

E.g.:

echo number_format (1000000);

Output:

1,000,000

14. print()

This simply outputs the string and is slower than the echo

Also, the print should not be used with ()

E.g.:

print "Hello";

Output:

Hello

15. md5()

This calculates the md5 hash of the string

E.g.:

echo md5 ("Hello");

Output:

8b1a9953c4611296a827abf8c47804d7

16. strtok()

This splits a string into smaller strings

E.g.:

$string = "This is to break a string";
$token = strtok ($string, " ");
echo($token); => This
To get all words of string,
while ($token !== false){
echo "$token<br>";
$token = strtok(" ");
}

Output:

This
is
to
break
string

17. strupper()

This converts a string to uppercase characters

E.g.:

echo strupper ("Beautiful Day");

Output:

BEAUTIFUL DAY

Note: strlower() converts strings to all lowercase characters.

18. substr()

This returns part of the string starting with the index specified

E.g.:

echo subst ("A Hot Day", 3);

Output:

ot Day

19. substr_replace()

This PHP string function replaces a part of the string with the string specified.

E.g.:

echo substr_replace ("Hot", "Day",0);

Output:

Day

20. wordwrap()

This wraps a string to a number of characters

E.g.:

echo wordwrap ("Hello World", 5, "\n");

Output:

Hello
World

21. Strlen()

This is used to determine the length of the string passed

E.g.:

echo strlen ("Hello");

Output:

5

22. Strrev()

This PHP string function is used to get the reverse of the string

E.g.:

echo strrev ("welcome");

Output:

emoclew

23. Strpos()

This returns the position of the first occurrence of a string inside a string

E.g.:

echo strops("There you go", "go");

Output:

11

24. Str_repeat()

This repeats a string specified number of times

E.g.:

echo str_repeat ('b', 5);

Output:

bbbbb

25. Str_replace()

This PHP string function finds the specified word, replaces that with a specified word, and return the string

E.g.:

echo str_replace ("great", "wonderful", "have a great day");

Output:

have a wonderful day

26. Nl2br()

This PHP string function inserts html line breaks in front of each new line of the string

E.g.:

echo nl2br ("Lets break \nthe sentence");

Output:

Lets break

the sentence

27. similar_text()

This calculates the similarity between two strings

E.g.:

echo similar_text ("Hello World","Great World");

Output:

7

28. sprintf()

This PHP string function writes a formatted string to a variable

E.g.:

echo sprintf ("There are %u wonders in the World",7);

Output:

There are 7 wonders in the World

29. Str_ireplace()

This replaces characters in the string with specific characters. This function is case insensitive.

E.g.:

echo str_ireplace ("great", "WOW", "This is a great place");

Output:

This is a wow place

30. str_shuffle()

This randomly shuffles all characters in a string

E.g.:

echo str_shuffle("Hello World");

Output:

lloeWlHdro

31. str_word_count()

This PHP string function returns the number of words in the given string

E.g.:

echo str_word_count ("a nice day");

Output:

3

32. Strcspn()

This returns the number of characters before the specified character

echo strcspn ("Hello world!","w");

Output:

6

33. str_pad()

This function is used to pad to the right side of the string, a specified number of characters with the specified character

E.g.:

echo str_pad ("Hello", 10, ".");

Output:

Hello…..

34. Ord()

This PHP string function returns the ASCII value of the first character of the string.

E.g.:

echo ord ("hello");

Output:

104

35. Strchr()

Find the first occurrence of a specified string within a string

E.g.:

echo strchr ("Hello world!", "world");

Output:

world!

36. Strspn()

This returns the number of characters found in the string that contains characters from the specified string.

E.g.:

echo strspn ("Hello world!", "Hl");

Output:

1

There are few more string functions available in PHP. The above string functions are commonly used functions in PHP for various requirements.

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