The string functions allow you to manipulate strings, it's part of the PHP core, and there is no installation required; to use these functions.
Trimming Strings
| Function | Description |
|---|---|
| trim() | Removes whitespace at the beginning and end of a string. |
| ltrim() | Removes whitespace at the beginning of a string. |
| rtrim() | Removes whitespace at the end of a string. |
Presentation
| Function | Description |
|---|---|
| htmlentities() | Escapes all HTML entities. |
| nl2br() | Inserts a <br /> tag before each newline character in a string. |
| strtoupper() | Converts a string to uppercase. |
| strtolower() | Converts a string to lowercase. |
| ucfirst() | Converts the first character of a string to uppercase. |
| ucwords() | Converts the first character of each word in a string to uppercase. |
Converting Strings and Arrays
| Function | Description |
|---|---|
| explode() | Splits a string into an array on a specified character or group of characters. |
| implode() | Converts an array into a string, placing a specified character or group of characters between each array element. |
| join() | Same as implode(). |
Substrings
| Function | Description |
|---|---|
| substr(str,pos) | Returns the substring from the character in position pos to the end of the string. |
| substr(str,-len) | Returns the substring from len characters from the end of the string to the end of the string. |
| substr(str,pos,len) | Returns a len length substring beginning with the character in position pos. |
| substr(str,pos,-len) | Returns a substring beginning with the character in position pos and chopping off the last len characters of the string. |
| strstr(haystack,needle,before_needle) | If the third argument (before_needle) is false (default), then it returns the part of the haystack from the needle on.If the third argument (before_needle) is true, then it returns the part of the haystack before the needle.The needle can be a string or an integer (or a number that can be converted to an integer). |
| stristr(haystack,needle,before_needle) | Same as strstr(), but case insensitive. |
| strpos(haystack,needle) | Finds the position of the first occurrence of a specified needle in a haystack (string).The needle can be a string or an integer (or a number that can be converted to an integer). |
| strrpos(haystack,needle) | Finds the position of the last occurrence of a specified needle in a haystack (string).The needle can be a string or an integer (or a number that can be converted to an integer). |
| str_replace() | Replaces all occurrences of one string with another string. |
Comparing Strings
| Function | Description |
|---|---|
| strcmp() | Compares two strings. Returns < 0 if str1 is less than str2, > 0 if str1 is greater than str2, and 0 if they are equal. |
| strcasecmp() | Like strcmp() but case insensitive. |
| strlen() | Returns the length of a string. |
More Functions
- addcslashes - Quote string with slashes in a C style
- addslashes - Quote string with slashes
- bin2hex - Convert binary data into hexadecimal representation
- chop - Alias of rtrim
- chr - Return a specific character
- chunk_split - Split a string into smaller chunks
- convert_cyr_string - Convert from one Cyrillic character set to another
- convert_uudecode - Decode a uuencoded string
- convert_uuencode - Uuencode a string
- count_chars - Return information about characters used in a string
- crc32 - Calculates the crc32 polynomial of a string
- crypt - One-way string encryption (hashing)
- echo - Output one or more strings
- explode - Split a string by string
- fprintf - Write a formatted string to a 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
- 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 - Join array elements with a string
- join - Alias of implode
- lcfirst - Make a string's first character lowercase
- levenshtein - Calculate the Levenshtein distance between two strings
- localeconv - Get numeric formatting information
- ltrim - Strip whitespace (or other characters) from the beginning of a string
- md5_file - Calculates the md5 hash of a given file
- md5 - Calculate the md5 hash of a string
- metaphone - Calculate the metaphone key of a string
- money_format - Formats a number as a currency string
- nl_langinfo - Query language and locale information
- nl2br - Inserts HTML line breaks before all newlines in a string
- number_format - Format a number with grouped thousands
- ord - Return ASCII value of a character
- 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
- quotemeta - Quote meta characters
- rtrim - Strip whitespace (or other characters) from the end of a string
- setlocale - Set locale information
- sha1_file - Calculate the sha1 hash of a file
- sha1 - Calculate the sha1 hash of a string
- 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 - Case-insensitive version of str_replace.
- str_pad - Pad a string to a certain length with another string
- str_repeat - Repeat a string
- str_replace - Replace all occurrences of the search string with the replacement string
- str_rot13 - Perform the rot13 transform on a string
- str_shuffle - Randomly shuffles a string
- str_split - Convert a string to an array
- str_word_count - Return information about words used in a string
- strcasecmp - Binary safe case-insensitive string comparison
- strchr - Alias of strstr
- strcmp - Binary safe string comparison
- strcoll - Locale based string comparison
- strcspn - Find a length of initial segment not matching the mask
- strip_tags - Strip HTML and PHP tags from a string
- stripcslashes - Un-quote string quoted with addcslashes
- stripos - Find position of first occurrence of a case-insensitive string
- stripslashes - Un-quote string quoted with addslashes
- stristr - Case-insensitive strstr
- strlen - Get string length
- strnatcasecmp - Case insensitive string comparisons using a "natural order" algorithm
- strnatcmp - String comparisons using a "natural order" algorithm
- strncasecmp - Binary safe case-insensitive string comparison of the first n characters
- strncmp - Binary safe string comparison of the first n characters
- strpbrk - Search a string for any of a set of characters
- strpos - Find the position of the first occurrence of a string
- strrchr - Find the last occurrence of a character in a string
- strrev - Reverse a string
- strripos - Find the position of the last occurrence of a case-insensitive string in a string
- strrpos - Find the position of the last occurrence of a char in a string
- strspn - Find the length of initial segment matching mask
- strstr - Find the first occurrence of a string
- strtok - Tokenize string
- strtolower - Make a string lowercase
- strtoupper - Make a string uppercase
- strtr - Translate certain characters
- substr_compare - Binary safe comparison of 2 strings from an offset, up to length characters
- substr_count - Count the number of substring occurrences
- substr_replace - Replace text within a portion of a string
- substr - Return part of a string
- trim - Strip whitespace (or other characters) from the beginning and end of a string
- ucfirst - Make a string's first character uppercase
- ucwords - Uppercase the first character of each word in a string
- vfprintf - Write a formatted string to a stream
- vprintf - Output a formatted string
- vsprintf - Return a formatted string
- wordwrap - Wraps a string to a given number of characters