PHP String Functions
A string is a combination of characters and string functions in a programming language are used to manipulate strings. For example:
$string = “PHP string handling functions.”;
Difference between single and double quoted strings in Php
In single quoted strings, variables are not interpreted and the whole string is printed as it is. However, in double quoted strings PHP has to parse the variables, examine their values and print accordingly.
Code example
Escape sequencing in Php:
Escape sequences are used to escape a character while string parsing and giving an additional meaning to it like line breaks, tabs etc. Escape sequences work in double quote strings. Escape sequences start with a backslash() followed by a character. Escape sequences used in PHP are as follows:
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Is replaced by a single quote |
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Is replaced by a double quote |
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To add line breaks within string |
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To add tab space |
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For carriage return |
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Is replaced by a dollar sign itself |
Code example
Php string handling functions
Function Name | Description | |
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addcslashes |
Returns a string after adding backslashes in front of mentioned character
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addslashes |
Returns a string after adding backslashes in front of predefined characters
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bin2hex |
Converts binary to hexadecimal
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chop |
Removes whitespace or any other predefined character from the right end of a string
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chr |
Converts a number to single-byte string
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chunk_split |
Splits a string into smaller chunks
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convert_cyr_string |
Converts one cyrillic character set to another
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convert_uudecode |
Decodes uuencoded string
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convert_uuencode |
Encodes the string in uuencode algorithm of encoding convert_uuencode(string) //syntax |
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count_chars |
Information about characters used in the string
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crc32 |
Calculates crc32 of a string
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crypt |
One way string hashing
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echo |
Output data or result on screen
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explode |
Splits a string into an array
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fprintf |
Writes a formatted string to any stream
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get_html_translation_table |
Returns the translation table used by htmlspecialchars and htmlentities get_html_translation_table(table, flag, encoding) //syntax |
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hebrev |
Converts hebrew text to visual text
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hebrevc |
Converts hebrew text to visual text
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hex2bin |
Converts hexadecimal to binary
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html_entity_decode |
Converts html entities to characters
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htmlentities |
Converts characters to html entities
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htmlspecialchars_decode |
Converts special HTML entities to characters
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htmlspecialchars |
Converts special characters to HTML entities
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implode |
Binds an array into a string implode(binder, array) //syntax |
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join |
Binds an array into a string
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lcfirst |
Converts first character of a string to lowercase |
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levenshtein |
Returns the levenshtein distance between two strings.Number of characters that will be replaced to transform string1 to string 2. |
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localeconv |
Returns numeric formatting information |
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ltrim |
Removes whitespace and other predefined characters from the left side of a string |
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md5 |
Calculates md5 hash of a string |
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md5_file |
Calculates md5 hash of a file |
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metaphone |
Calculates metaphone key of a string |
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money_format |
Formats a number as currency |
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nl_langinfo |
Locale information |
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nl2br |
Inserts HTML line breaks in front of all new lines |
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number_format |
Formats to number |
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ord |
Returns the ASCII value of the first character of the string |
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parse_str |
To parse a query string to a variable |
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Used to output string |
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printf |
Prints a formatted string |
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quoted_printable_decode |
Converts a quoted-printable string to an 8-bit string |
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quoted_printable_encode |
Converts an 8-bit string to a quoted printable string |
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quotemeta |
Quotes metacharacters |
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rtrim |
Removes the whitespace or specified characters from the right side of the string |
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setlocale |
Sets the locale information |
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sha1 |
Calculates the SHA-1 hash of a string |
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sha1_file |
Calculates the SHA-1 hash of a file |
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similar_text |
Checks for the similarity between two strings |
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soundex |
Calculates the soundex key of a string |
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sprintf |
Returns a formatted string |
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sscanf |
Converts input from a string as per the given format |
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str_getcsv |
Converts CSV string into an array |
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str_ireplace |
Case insensitive while replacing some characters in a string. |
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str_pad |
Pads a string to specified length |
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str_repeat |
Repeats a string for a specified number of times |
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str_replace |
Replaces specified characters in a string |
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str_rot13 |
Encodes a string by ROT13 method |
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str_shuffle |
Shuffles a string randomly |
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str_split |
Splits a string into an array |
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str_word_count |
Counts the number of words in a string |
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strcasecmp |
Case insensitive string comparison |
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strchr |
Checks for the first occurrence of the string |
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strcmp |
Case sensitive string comparison |
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strcoll |
Locale based string comparison |
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strcspn |
Returns the count of numbers found in a string before a matching mask |
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strip_tags |
Strips HTML and PHP tags from a string |
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stripcslashes |
Unquotes a string being quoted by addcslashes |
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stripslashes |
Unquotes a quoted string |
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stripos |
Case insensitive search of a string for the first occurrence of a string inside another |
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stristr |
Case-insensitive search for the first occurrence of a string inside another string. |
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strlen |
Returns the length of string |
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strnatcasecmp |
Case insensitive comparison of two strings using Natural Order Algorithm |
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strnatcmp |
Case sensitive comparison of two strings using Natural Order Algorithm |
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strncasecmp |
Case insensitive comparison of strings for first n characters |
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strncmp |
Case sensitive comparison of strings for first n characters |
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strpbrk |
Search a string for any set of characters |
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strpos |
Checks a string for the position of first occurrence of a specified string. Searching is case sensitive |
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strrchr |
Checks a string for the last occurrence of a specified string |
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strrev |
Reverse the string |
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strripos |
Checks a string for the position of last occurrence of a specified string. Searching is case insensitive |
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strrpos |
Checks a string for the position of last occurrence of a specified string. Searching is case sensitive |
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strspn |
Returns the number of characters found in a string which has characters from specified charlist |
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strstr |
Checks for the first occurrence of the string |
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strtok |
Tokenize the string |
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strtolower |
Converts whole string to lowercase |
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strtoupper |
Converts whole string to UPPERCASE |
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strtr |
Translate characters to string |
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substr |
Returns a part of the string |
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substr_compare |
Compare two strings with defined start position |
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substr_count |
Count the number of substring existence in a string |
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substr_replace |
Replaces substring with a defined string |
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trim |
Removes whitespace and predefined characters from both sides of a string |
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ucfirst |
Converts the first character of string to uppercase |
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ucwords |
Converts the first character of each word in a string to uppercase |
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vfprintf |
Writes a formatted string to a stream |
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vprintf |
Prints a formatted string |
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vsprintf |
Returns a formatted string |
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wordwrap |
Wraps a string to a mentioned number of characters |