[PHP] Practical functions 5_PHP tutorial

//Convert the binary representation of a number into hexadecimal

string bin2hex(string tring)
//Remove the spaces at the end of the string

string rtrim(string string )
//An alias for rtrim

string chop(string string)
//Remove spaces from both ends of the string

string trim(string string)
// Remove spaces from the beginning of the string

string ltrim(string string)
//Use string separator to split the string string and return the components of the string string in the array

array explode(string separator,string string)
//By adding glue string between each element of array pieces, combine the elements and return a string

string implode(string glue,array pieces)
//Makes a string uppercase

string strtoupper(string string)
//Makes a string lowercase

string strtolower(string string)
//Convert the same strings in strings str and from into strings in to one by one and return

string strtr(string str,string from,string to)
//Find the position of the first occurrence (case-insensitive) of a character in one string in another string

int strpos(string haystack,string needle,int [offset])
//Find the last position where the character in the string appears in another string. It is worth noting that needle can only be one character.
Chinese characters are not suitable for

int strrpos(string haystack,char needle)
//Change the string into small segments for use by other functions. For example, base64_encode. The default is that the parameter chunklen (76 characters) inserts end(" ") every
76 characters. Returns a new string without modifying the original string.

string chunck_split(string string,int[chunklen],string[end])
//Extract length characters from the start position of string string. If start is a negative number, it starts from the end of the string
. If the omitted parameter length exists but is a negative number, it means that the penultimate length character is obtained

string substr(string string,int start,int[length])
//returned string The following characters are preceded by a backslash (): .+*?[^](＄)

string quotemeta(string str)
//Returns the ASCII (American National Standard) of the string exchange code) ordinal value. This function is opposite to the chr() function

int ord(string string)
//Convert the ASCII code into a character

string chr(int ascii)
//Use Capitalize the first character of a string

string ucfirst(string str)
//Capitalize the first character of each word in a string

string ucwords(string str)
//Compare the similarity between two characters and return the number of identical character sequences (chars) in the two strings. By using the reference variable given by
in the third parameter, pass the percentage of similar characters to The third parameter

int similar_text(string first,string second,double[percent]
//Convert single quotes, double quotes and backslash characters in a character with backslashes Definition

string addslashes(string str)
//Remove backslashes from the string

string stripslashes(string str)
//Use pattern rules to analyze the comparison For string string, the value returned by the comparison result is placed in the array parameter regs. The content of regs[0]
is the original string string. regs[1] is the first string that conforms to the rules. regs[2 ] is the second regular string
, and so on. If the parameter regs is omitted, it is simply compared. If found, the return value is true

int ereg(string pattern,string string ,array)[regs])
//Similar to ereg(), the difference is that ereg() is case-sensitive, this function has nothing to do with case

int eregi(string pattern,string string, array[regs])
//This function uses pattern rules to analyze and compare string strings, and the character to be replaced is the parameter replacement. The return value
is a string type

string ereg_replace(string pattern,string replacement,string string)
//Construct a case-insensitive replacement regular expression

string eregi_replace(string pattern,string replacement,string string)
//The return value after cutting is an array variable. The parameter pattern is the specified rule string, the parameter string is the string to be processed
, and the parameter limit can be omitted, indicating that the maximum number of qualified values ​​to be processed is. It is worth noting that the pattern parameter of this function is case-sensitive

array split(string pattern,string string,int[limit])
//This function can return the characters of the string to upper and lower cases word by word .In PHP use, this function has no effect, but it may be able to provide external
processing or database processing.

string sql_regcase(string string)
//Storage data in byte-stream mode. Variable value is a mixed type, which can include integers, double-precision floating-point number strings, arrays,
and object properties (object methods are not saved)

string serialize(mixed value)
// Data stored in the system in byte-stream mode can be retrieved

mixed unserialize(string str)