PHP string functions and usage analysis_PHP tutorial

AddSlashes: Add slashes to the string.
bin2hex: Convert binary to hexadecimal.
Chop: Remove consecutive blanks.
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 into 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: Convert URL-specific format string to normal string.
rawurlencode: Encode a string into a 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 tags.
StripSlashes: Strips 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.

addslashes
Return value: string
Function type: Data processing
Content description: This function adds slashes to the quotation marks of the string that needs to be processed by the database so that the database query can operate smoothly. The characters that will be modified include single quotes (), double quotes ("), backslash () and the null character NUL (the null byte).
Reference: stripslashes() htmlspecialchars() quotemeta()

bin2hex
Return value: string
Function type: Data processing
Content description: This function converts a binary string into a hexadecimal string.
Usage example
Supplement:
josh@superfork.com (22-Jun-1999) wrote a function that can convert hexadecimal to binary.
function hex2bin($data) {
$len = strlen($data);
for($i=0;$i<$len;$i+=2) {
$newdata .= pack("C",hexdec(substr($string,$i,2)));
}
return $newdata;
}
?>

chop
Return value: string
Function type: Data processing
Content description: This function clears consecutive blanks in a string.
Usage examples
$trimmed = Chop($line);
?>
Reference: trim()

chr
Return value: string
Function type: Data processing
Content description: This function converts the ordinal number of characters into ASCII characters. This function is in contrast to ord().