PHP Strings, Easy To Learn Strings Tutorial in PHP

PHP Strings

A string is sequence(series) of characters. where every character is the same as a byte. i.e. used to store and manipulate text.

A string literal can be specified in three different ways.

single quoted : 'Hello world!'

double quoted : "Hello world!"

heredoc syntax : strings is by using heredoc syntax ("<<<").

PHP String - Single quoted

We can create a string in PHP by enclosing text in a single quote.

<!DOCTYPE html>
<html>
<head>
	<title>PHP String - Single quoted</title>
</head>

<body>

<?php
	$str='Welcome to Free Time Learning(www.freetimelearning.com).';  
	echo $str;  ;
?>


</body>
</html>

Output :

PHP String - Double quoted

In PHP, we can specify string through enclosing text within double quote also. But escape sequences and variables will be interpreted using double quote PHP strings.

<!DOCTYPE html>
<html>
<head>
	<title>PHP String - Double quoted</title>
</head>

<body>

<?php
	$str="Welcome to Free Time Learning(www.freetimelearning.com).";  
	echo $str;  ;
?>

</body>
</html>

Output :

PHP String Functions

PHP provides various string functions to access and manipulate strings. A list of important PHP string functions are given below.

Function	Description
`addcslashes()`	Returns a string with backslashes before the specified characters
`addslashes()`	Returns a string with backslashes in front of predefined characters
`bin2hex()`	Convert binary data into hexadecimal values
`chop()`	Removes whitespace or other characters from the right end of a string
`chr()`	Returns a one-character string containing the character specified by ASCII
`chunk_split()`	Split a string into smaller chunks
`convert_cyr_string()`	Converts a string from one Cyrillic character set to another
`convert_uudecode()`	Decodes a uuencoded string
`convert_uuencode()`	Encodes a string using the uuencode algorithm
`count_chars()`	Return information about characters used in a string
`crc32()`	Calculates the crc32 polynomial of a string
`crypt()`	One-way string encryption (or hashing)
`echo()`	Output one or more strings
`explode()`	Split a string into an array by a specified string
`fprintf()`	Write a formatted string to a specified output stream
`get_html_translation_table()`	Returns the translation table used by `htmlspecialchars()` and `htmlentities()`
`hebrev()`	Convert logical Hebrew text to visual text
`hebrevc()`	Convert logical Hebrew text to visual text with newline conversion
`hex2bin()`	Decodes a hexadecimally encoded binary string
`html_entity_decode()`	Convert all HTML entities to their applicable characters
`htmlentities()`	Convert all applicable characters to HTML entities
`htmlspecialchars_decode()`	Convert special HTML entities back to characters
`htmlspecialchars()`	Convert special characters to HTML entities
`implode()`	Return a string by joining the elements of an array with a specified string
`join()`	Alias of `implode()`
`lcfirst()`	Converts the first character of a string to lowercase
`levenshtein()`	Calculate Levenshtein distance between two strings
`localeconv()`	Returns localized numeric and monetary formatting information
`ltrim()`	Removes whitespace (or other characters) from the beginning of a string
`md5()`	Calculate the md5 hash of a string
`md5_file()`	Calculates the md5 hash of a file
`metaphone()`	Calculate the metaphone key of a string
`money_format()`	Formats a number as a currency string
`nl_langinfo()`	Returns specific local information
`nl2br()`	Inserts HTML line breaks before all newlines in a string
`number_format()`	Format a number with grouped thousands
`ord()`	Returns the ASCII value of the first character of a string
`parse_str()`	Parses the string into variables
`print()`	Output a string
`printf()`	Output a formatted string
`quoted_printable_decode()`	Convert a quoted-printable string to an 8 bit string
`quoted_printable_encode()`	Convert a 8 bit string to a quoted-printable string
`quotemeta()`	Quotes meta characters
`rtrim()`	Removes whitespace (or other characters) from the end of a string
`setlocale()`	Set locale information
`sha1()`	Calculate the sha1 hash of a string
`sha1_file()`	Calculate the sha1 hash of a file
`similar_text()`	Calculate the similarity between two strings
`soundex()`	Calculate the soundex key of a string
`sprintf()`	Return a formatted string
`sscanf()`	Parses input from a string according to a format
`str_getcsv()`	Parse a CSV string into an array
`str_ireplace()`	Replace all occurrences of the search string with the replacement string. Case-insensitive version of `str_replace()`.
`str_pad()`	Pad a string to a certain length with another string
`str_repeat()`	Repeats a string a specified number of times
`str_replace()`	Replace all occurrences of the search string with the replacement string (case-sensitive)
`str_rot13()`	Performs the ROT13 encoding on a string
`str_shuffle()`	Randomly shuffles all characters in a string
`str_split()`	Splits a string into an array
`str_word_count()`	Counts the number of words in a string
`strcasecmp()`	Binary safe comparison of two string (case-insensitive)
`strchr()`	Finds the first occurrence of a string inside another string. Alias of `strstr()`
`strcmp()`	Binary safe comparison of two string (case sensitive)
`strcoll()`	Locale based comparison of two string (case sensitive)
`strcspn()`	Returns the number of characters found in a string before any part of some specified characters are found
`strip_tags()`	Strip HTML and PHP tags from a string
`stripcslashes()`	Un-quotes a string quoted with `addcslashes()`
`stripos()`	Find the position of the first occurrence of a case-insensitive substring in a string
`stripslashes()`	Un-quotes a quoted string
`stristr()`	Finds the first occurrence of a string inside another string (case-insensitive). Case-insensitive version of `strstr()`
`strlen()`	Returns the length of a string
`strnatcasecmp()`	Compares two strings using a "natural order" algorithm (case-insensitive)
`strnatcmp()`	Compares two strings using a "natural order" algorithm (case-sensitive)
`strncasecmp()`	Binary safe string comparison of the first n characters (case-insensitive)
`strncmp()`	Binary safe string comparison of the first n characters (case-sensitive)
`strpbrk()`	Searches a string for any of a set of characters
`strpos()`	Find the position of the first occurrence of a substring in a string
`strrchr()`	Find the last occurrence of a character in a string
`strrev()`	Reverses a string
`strripos()`	Find the position of the last occurrence of a string inside another string (case-insensitive)
`strrpos()`	Find the position of the last occurrence of a string inside another string (case-sensitive)
`strspn()`	Returns the number of characters found in a string that contains only characters from a specified charlist
`strstr()`	Find the first occurrence of a string inside another string (case-sensitive)
`strtok()`	Splits a string into smaller strings
`strtolower()`	Converts a string to lowercase
`strtoupper()`	Converts a string to uppercase
`strtr()`	Translate characters or replace substrings
`substr()`	Return a part of a string
`substr_compare()`	Compares of two strings from a specified start position up to the length of the comparison. The comparison is binary safe and optionally case-sensitive
`substr_count()`	Counts the number of times a substring occurs in a string
`substr_replace()`	Replaces a part of a string with another string
`trim()`	Removes whitespace (or other characters) from the beginning and end of a string
`ucfirst()`	Converts the first character of a string to uppercase
`ucwords()`	Converts the first character of each word in a string to uppercase
`vfprintf()`	Write a formatted string to a specified output stream
`vprintf()`	Output a formatted string
`vsprintf()`	Return a formatted string
`wordwrap()`	Wraps a string to a given number of characters

PHP strlen() function

The strlen() function is used to calculate the number of characters inside a string. It also includes the blank spaces inside the string.

<!DOCTYPE html>
<html>
<head>
	<title>PHP strlen() function</title>
</head>

<body>


<?php
	echo strlen("Free Time Learning");
?>

</body>
</html>

Output :

PHP str_word_count() function

The PHP str_word_count() function counts the number of words in a string:

<!DOCTYPE html>
<html>
<head>
	<title>PHP str_word_count() function</title>
</head>

<body>


<?php
	echo str_word_count("Free Time Learning");
?>

</body>
</html>

Output :

PHP str_replace() function

The str_replace() replaces all occurrences of the search text within the target string.

<!DOCTYPE html>
<html>
<head>
	<title>PHP str_replace() function</title>
</head>

<body>


<?php
	echo str_replace("Time", "Learning", "Free Time");
?>

</body>
</html>

Output :

PHP strrev() function

The strrev() function reverses a string.

<!DOCTYPE html>
<html>
<head>
	<title>PHP strrev() function</title>
</head>

<body>


<?php
$ftl = 'Free Time Learning';
 
// Display reversed string
	echo strrev($ftl);
?>

</body>
</html>

Output :

PHP strtoupper() function

The strtoupper() function returns string in uppercase letter.

<!DOCTYPE html>
<html>
<head>
	<title>PHP strtoupper() function</title>
</head>

<body>


<?php
$ftl = 'Free Time Learning';
 
   // Upper case Letters
	echo strtoupper($ftl);
?>

</body>
</html>

Output :

PHP strtolower() function

The strtolower() function returns string in lowercase letter.

<!DOCTYPE html>
<html>
<head>
	<title>PHP strtolower() function</title>
</head>

<body>


<?php
$ftl = 'Free Time Learning';
 
   // Upper case Letters
	echo strtolower($ftl);
?>

</body>
</html>

Output :

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