Summary and sharing of commonly used PHP letters

php functions are the only way to learn php. What are the commonly used php functions? This article mainly shares with you a summary of commonly used PHP letters, hoping to help everyone.

array()

array(value1,value2…..) Create an array

array_chunk(array,size,preserve_keys) Split a number Into a new array block [tʃʌŋk]

array_combine(keys,values) Form a new array by merging two arrays (key array, key value array)

array_count_values( array) Used to count the number of occurrences of all values ​​in the array

array_diff(array1,array2,...) Comparing arrays returns the difference between two arrays (only keys are compared Value)

array_diff_assoc(array1,array2,..) Compare arrays and return the difference set of two arrays (compare key names and key values)

array_diff_key( array1,array2,...) Comparing arrays returns the difference between two arrays (only comparing key names)

array_fill(index,number,value) Using the given Fill the array with key values

array_filter(array, the callback function to be used) Use the callback function to filter the elements in the array

array_flip(array) Reverse/exchange the key names in the array and the corresponding associated Key value [flɪp]

array_keys(array)                                                                                                                                                                                                               possible An array [mɜ:rdʒ]

array_pad(array,size,value) Inserts the specified number of elements with the specified value into the array

array_pop(

array)                                                                                                      array_push(array)                                                                                                                                  (array

())                                                                                     array_unshift(array

))                                                                                                    The first element

AddOne or more elementsarray_rand(array,number) Randomly select one from the array Or multiple arraysarray_replace(array1,array2...) Use the value of the following array to replace the value of the first array

array_reverse(array) Reverse the array and return a new array

array_search(value,array, strict(optional true, flase)) Search value returns key name. True searches for elements with the same key name and value

array_slice(array,start,length,preserve) Returns the selected part of the array

array_splice(array,start,length,array) Remove the specified elements and replace them with others

array_unique(array) Delete duplicate values ​​in the array US [juˈnik ]

array_values(array)                                                                                                                     lapse             out out out out of Error in the Array

count(

array)                  返回数组中元素的数目美 [kaʊnt]

in_array 

('值

',$array, bool

)     Check whether the specified value exists in the array is set to TRUE, then the in_array function checks the search Whether the data and array values ​​are of the same type. key(array

)                                                                                                                                              getting the key name from the associative array

list(

array1, array2…)                                             , none herself fieldtenttenttenttent the the given the value of the array assigned to some Array variable

KRSORT (

Array ) to sort the associated array key name

数 (

array ) #arsort(

array

) Sort the associative array in descending order by key valueasort(

array

) Sort the associative array in ascending order of key value

String

strtolower(string) Convert the string to lowercase letters

strtoupper(string) Convert the string to uppercase lettersstrtr(" string”,”from”,””to”) Convert the undetermined characters in the string

substr(string,start, length) Return a part of the string

substr_count(

string ,substring,start,length

) Calculate the number of times a substring appears in a string

substr_replace(

string,inserted characters,start,length )

Replace part of the string with another charactertrim(string,which characters (optional)) Remove blank characters and other characters trim on both sides of the string ucfirst(string) Convert the first character of the string to uppercase

ucwords(string) Convert each character of the string Convert the first character to uppercase sha1(

string, optional character

) Calculate the SHA-1 hash of the string

sha1_file(file) Calculate the SHA hash of the file

sprintf(How to format the variables)           Write the formatted string into a variable

str_getcsv(string, delimiter , Surround character, escape character) Parse the CSV string into an array

str_ireplace(Find value, replace value) Replace some characters in the string (case insensitive) Sensitive)

Str_pad (# String, Length ##) Fill the string into a new length

# Str_repeat (

string, number # #) Repeat the string a specified number of times

str_replace(

Find value, replace value) Replace some characters of the string (case sensitive)

str_shuffle(string) Randomly shuffle all the characters of the string US [ˈʃʌfəl] shuffle/chaos

str_split

(string.length) Split the string into an array

str_word_count(

string) Calculate the length of the word in the string

strchr(

string,search,before_search) Find the first occurrence of a string in another string strstr()

implode(

content,array) Return a string composed of array elements US [ ɪmˈploʊd]

lcfirst(string ) Convert the first character of the string to lowercase

ltrim(

string, defined character ) Remove the blank characters on the left side of the string or Other characters

md5(string) Calculate the MD5 hash

md5_file(file) Calculate the MD5 hash of the file

ord(string) Return the first character in the string The ASCII code value

parse_str(

string,array(optional) Parses the query string into a variable

printf(format value) Outputs the formatted string

print(strings) Output one or more strings

strip_tags(string) Strip HTML and PHP tags from strings

stripcslashes(string) Removed by addcslashes( ) backslashes added by the function lashes [læʃ]

stripslashaes string () Delete the backslashes added by the addslashees() function

stripos(

string,find,start ) Returns the position of the first occurrence of a string in another string (case insensitive)

stristr(

search, searched string) Finds a string in another string The position of the first occurrence in (insensitive to case)

strlen(string) Returns the length of the string

strpos(

string, the character to be found) Returns The position of the first occurrence of a string in another string (case insensitive)

strrchr(

string, the character to be searched for) Find the last string in another string One occurrence of

strrev(string) reverses the string.

strripos(

string,search character) Find the last occurrence of a string in another string (case insensitive)

strrpos(string, the character to be searched for) Find the last occurrence of a string in another string (case insensitive)

addcslashes(string, Range) Returns a string with a backslash added before the specified character

addslashes(string) Returns a string with a backslash added before the predefined character

chr( ASCII value. ) Returns characters from the specified ASCII code value

chunk_split(string,length,end) Splits the string into a series of smaller parts

count_chars() Return the character information used in the string

echo(strings) Output one or more strings

explode() Expand the characters into an array

#Date

date_default_timezone_get() Returns the default time zone used by all Date/Time functions

date_default_timezone_set() Sets the default time zone used by all Date/Time functions

date( ) Format local date and time

time() Returns the Unix timestamp of the current time

# Pi () Return the value of the period of PI

POW (x, y) Return to X's y back-ups

# Rand () Return to random integer (0-1)

round()                                                                                                                       use use using that that with down to the same over as down as down as being being being being being being over being be over being over being over being toward being worth before being over being toward be worth toward worth before being worth' be' worth' you'''''' myself's‐'

round's' be so so so so so so so so so so so so so so so so so so so so so so so so so so so so so so so so so so so so so so so so so so so so...

##max()                                                                                                                                                         forward to get the direct value in the array. #is_nan() Determine whether it is a non-numeric value

File

##fwrite(file,string,length)

Write Open file

is_dir(file) Determine whether the file is in the same directory

is_file(file) Determine whether the file is a regular file

mkdir(

Directory name

)                                                                                                                                                                          #

rename(file)                                                                                                                                   From a named file or directory     

rmdir (      Directory )                                      out out out out off out out out out out out through out through out through out using ‘’’’’         ’’’’ out out out out through out through out through'''‐'''‐''‐''‐through through to be filesize(filename) Returns the file size

fopen(

filename,type

) Opens a file or URL

fputs(file,string,length) The content is written to an open file Alias ​​of fwrite()

fread(file,length) Read the open filefseek(file, new position) Position in the open file

copy(file,to_file) Copy the file to the destination

dirname(path path) Return the directory name part of the path

fclose(file) Close the open file

fgetc(file) Returns characters from an open file

fgetcsv(file) Parses a line from an open file, validating CSV fields

fgets(file) open Return a line from the file

fgetss(file) Return a line from the open file and filter out HTML and PHP

file(path) Read the file into the array

file_exists( file)                                                                                                                                                                                                                                                                                                 off out off out.

## Directory

# chdir (

Directory

) Change the current directory

CLOSEDIR (

Dir_handle available

#) Turn off the recorded handle

# Dir () Return to the instance of the Directory class

# Getcwd ( Directory

) Return to the current working directory

##11 OpenDir ( PATH) Open the directory handle Readdir ( Dir_handle available ) The condition of the directory handle

scandir(directory) Returns an array of files and directories in the specified directory

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