php string function_PHP tutorial

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addslashes: Add slashes to strings.
bin2hex: Convert binary to hexadecimal.
chop: Remove consecutive whitespace.
chr: Returns the ordinal value of a character.
chunk_split: Divide the string into small segments.
convert_cyr_string: Convert Cyrillic strings to other strings.
crypt: Encrypt the string using des encoding.
echo: output string.
explode: split the string.
flush: Clear the output buffer.
get_meta_tags: Extract the data of all meta tags in the file.
htmlspecialchars: Convert special characters to html format.
htmlentities: Convert all characters into html strings.
implode: Convert an array into a string.
join: Convert an array into a string.
ltrim: Remove consecutive whitespace.
md5: Computes the md5 hash of a string.
nl2br: Convert newline characters to
.
ord: Returns the ordinal value of a character.
parse_str: Parse query string into variables.
print: output string.
printf: output formatted string.
quoted_printable_decode: Convert qp encoded string into 8-bit string.
quotemeta: Add quote symbols.
rawurldecode: Restore the URL-specific format string to a normal string.
rawurlencode: Encode string into url-specific format.
setlocale: Configure localization information.
similar_text: Calculate string similarity.
soundex: Calculate the pronunciation value of a string
sprintf: Format strings.
strchr: Find the first occurrence of a character.
strcmp: String comparison.
strcspn: length of different strings.
strip_tags: Remove html and php tutorial tags.
strips tutorial lashes: remove backslash characters.
strlen: Get the length of the string.
strrpos: Find the last occurrence of a character in a string.
strpos: Find the first occurrence of a character in a string.
strrchr: Get the string starting from the last occurrence of a character.
strrev: Reverse a string.
strspn: Find the number of times a string falls within the mask of another string.
strstr: Returns the string from the beginning to the end of a string in the string.
strtok: Cut a string.
strtolower: Convert all strings to lowercase.
strtoupper: Convert the string to all uppercase letters.
str_replace: String replacement.
strtr: Convert certain characters.
substr: Get part of the string.
trim: Trim the spaces at the beginning and end of the string.
ucfirst: Change the first character of the string to uppercase.
ucwords: Capitalize the first letter of each word in the string.

The string functions in the PHP language are also relatively easy to understand. Today we have summarized nearly 12 PHP string functions for you. We hope it will be helpful to friends who need them again and increase the PHP knowledge base of readers and friends.
1Find character position function:
int strpos(string $str, mixed search,[int]): Find the position of the first occurrence of search in $str (starting from int, ignoring any value before int);
int stripos(string $str,string search,[int]): The function returns the position of the first occurrence of a string in another string. This function is not case sensitive
strrpos($str,search,[int]): Find the last occurrence of search in $str starting from int (starting from int, ignoring any value before int);

2. Extract sub-character function (double bytes)
submit($str,int start[,int length]): Extract [length-length string] starting from the strat position in $str.
strstr($str1,$str2): Search $str2 from $str1 (the first position) and intercept the string from it to the end; if not, return false.
The function of stristr() is the same as strstr, except that it is not case-sensitive.
strrchr() returns from the last character searched; use: to get the file name in the path
3. PHP string function to replace string
str_replace(search,replace,$str): Find search from $str and replace
with replace str_irreplace(search,replace,$str):
strtr($str,search,replace): replace in this function cannot be "";
substr_replace($str,$rep,$start[,length])$str original string, new one after $rep replacement
String, $start starting position, $length replacement length, this item is optional
4. Character length
int strlen($str)
5. Compare character function
int strcmp($str1,$str2):$str1>=<$str2 are positive 1,0,-1 respectively (string comparison)
strcasecmp() Same as above (case-insensitive)
strnatcmp("4","14") compares strings in natural order
strnatcasecmp() Same as above, (case sensitive)
6. PHP string function split into arrays
str_split($str,len): Split $str according to the length of len and return the array
split(search,$str[,int]): Split $str according to search characters and return the array int how many times it is split, and the rest will not be split
expload(search,$str[,int])
7. Remove spaces:
ltrim, rtrim, trim
8. Add space function
chunk_split($str,2); Press 2 characters into the $str character to add a space;
9. chr, ord--return the specified character or ascii
10. Functions related to html code
nl2br(): Convert n to
.
strip_tags($str[,'

']): remove html and php tags
All html and php codes in $str will be removed, and the optional parameters html and php codes will be retained
Optional parameter to write the code.
For example: echo strip_tags($text, '

');

htmlspecialchars($str[,parameter]): The normal output of the page html code parameters is the conversion method
11. PHP string function for character case conversion
strtolower($str) converts the string to lowercase
strtoupper($str) Convert string to uppercase
ucfirst($str) converts the first character of the function to uppercase
ucwords($str) converts the first letter of each word to uppercase
12. PHP string functions related to database tutorial
addslashes($str): Make single quotes ('), double quotes ("), backslashes () and nul
in str The string is converted to ',",.
magic_quotes_gpc = on automatically escapes the content of get post cookie
get_magic_quotes_gpc() detects whether magic_quotes_gpc is turned on
stripslashes() removes backslashes from strings