Detailed explanation of PHP basic function examples

This article mainly shares with you detailed examples of PHP basic functions, hoping to help everyone.

1. Functions related to output:

l print(): similar to the content provided by echo output, returning 1

l print_r() Generally used to print arrays , does not print the type

l var_dump(): print the value of the data, also There are types

2. Functions related to time

l date(): Display date and time

            Example: date(“Y-m-dH:i:s”)

l time(): timestamp (number of seconds)

l microtime (): Return the timestamp and microseconds

l strtotime(): Parse the date and time string into a timestamp

3 , Mathematics related functions:

l max($v1,$v2,$v3…) Find the maximum value

l min($v1,$v2,$v3…) Find Minimum value

l rand() random number

l mt_rand() generates a better random number

l round(variable[,N]) Keep n small bits

l ceil() Round up

l floor() Round down

l pow(x,y) Find xY

l abs( )Absolute value

l sqrt(): Find the square root

4. Functions related to functions

l function_exists('function name' ) Determine whether the function exists

l func_get_arg(subscript) Get the parameters corresponding to the specified subscript

l func_get_args(): Get in the custom function All parameters (the return value is an array)

l func_num_args(): Get the number of parameters of the current custom function

5. String-related functions

Basic function strlen(): get the length of the stringmb_strlen($string variable name, character encoding)

l implode (connection method, array): connect into one String

l explode(split character, target string): becomes array

l str_split(string, character length): Split characters according to the specified length The string is obtained as an array

l trim(string[,specified character]): The default is to remove the spaces on both sides of the string

l ltrim(): Remove the

## on the left #l rtrim(): Remove the

l on the right

substr(string, starting position starts from 0 [, length])

l

strstr (string, matching characters): Starting from the specified position, intercepting to the end (can be used to remove the file suffix name)

l strtolower(): all lowercase

l strtoupper() : All uppercase

l ucfirst(): Capitalize the first letter

l strpos (string, matching character): Determine the position where the character appears in the target string (first time)

l strrpos (string, matching characters)

l str_replace (matching target, replacement content, string itself)

l printf/sprintf (output string has placeholder, Sequential placeholder content..)%d %s

l str_repeat(): Repeat a string n times

l str_shuffle(): Shuffle the string randomly

6. Array-related functions

Array sorting functions

l

sort(): Sort by the value of the elements in ascending order (subscript rearrangement)

l

rsort(): Sort by the value of the elements in descending order (subscript rearrangement)

l

asort(): Sort by the value of the elements in ascending order (subscripts retained)

l

arsort(): Sort by the value of the elements in descending order (subscripts reserved) Reserved)

l

ksort(): Array key name (subscript) in ascending order, (subscript reserved)

l

krsort() : Arrange in descending order by key name, (subscripts retained)

l

shuffle(): Randomly shuffle the array elements, and the array subscripts will be rearranged

l Sort: The default is ascending order, if r is descending order)

l Yesa: Just keep the index relationship

l has k: issorted by key name

Pointer

l

reset() resets the pointer and returns the array pointer to the first position

l end() Reset the pointer and point the array pointer to the last element

l next() Move the pointer down to get the value of the next element

l prev() Move the pointer up to get the value of the previous element                                                        Move the pointer)

l key(): Get the subscript value corresponding to the current pointer (without moving the pointer)

Array Others Function

l count(): Count the number of elements in the array

l array_push(): Add an element to the array (After the array)

l array_pop(): Take out an element from the array (After the array)

l array_shift(): From the array Remove an element from the array (in front of the array)

l array_unshift(): Add an element from the array (in front of the array)

l array_reverse( ): Array elements are reversed

l in_array(): Determine whether an element exists in the array

l array_keys(): Get an All subscripts of the array, return an index array

l array_values(): Get all the values ​​of an array, return an index array

l array_merge():Merge one or more arrays

array_merge($arr1,$arr2)

l array_splice():Remove part of the array and replace it with other values

$input

<span style="color:#0000BB;">= array(</span><span style="color:#007700;">"red"</span><span style="color:#DD0000;">, </span><span style="color:#007700;">"green"</span><span style="color:#DD0000;">, </span><span style="color:#007700;">"blue"</span><span style="color:#DD0000;">, </span>##"yellow"<span style="color:#007700;"></span>);<span style="color:#DD0000;"></span><span style="color:#007700;"></span>array_splice
(<span style="color:#0000BB;"></span> $input<span style="color:#007700;"></span>##, <span style="color:#0000BB;"></span>2<span style="color:#007700;"></span>);<span style="color:#0000BB;"></span><span style="color:#007700;">//$input is now array(“red”,”</span> green

”);<span style="color:#0000BB;"></span>l array_chunk():<span style="color:#0000BB;">Split an array into multiple ones</span>l

shuffle():

Shuffle the arrayl

range():

Create an array containing the specified range unitl

is_file():

Judge whether the given file name is a normal filel

define():

Define a constantl

defined():

Check whether a constant with a certain name existsl

ini_set( ):

Set a value for a configuration option ini_set

(<span style="color:#0000BB;"></span>'display_errors'<span style="color:#007700;"></span>, <span style="color:#DD0000;"></span>'1'<span style="color:#007700;"></span>);<span style="color:#DD0000;"></span> l basename():<span style="color:#007700;">Return the file name part of the path</span>l

is_array():

Detect whether the variable is an arrayl

list():

Assign the values ​​in the array to some variables

<span style="color:#0000BB;">$info </span><span style="color:#007700;">= array(</span><span style="color:#DD0000;">'coffee'</span> <span style="color:#007700;">, </span><span style="color:#DD0000;">'brown'</span><span style="color:#007700;">, </span><span style="color:#DD0000;">'caffeine'</span> <span style="color:#007700;">);</span>
<span style="color:#007700;">list(</span><span style="color:#0000BB;">$drink</span><span style="color:#007700;">, </span><span style="color:#0000BB;">$color</span>##, <span style="color:#007700;"></span> $power<span style="color:#0000BB;"></span>##) = <span style="color:#007700;"></span>$info<span style="color:#0000BB;"></span>;<span style="color:#007700;"></span>
echo <span style="color:#007700;"></span>"<span style="color:#DD0000;"></span>$drink<span style="color:#0000BB;"></span> is <span style="color:#DD0000;"></span>$color<span style="color:#0000BB;"></span> and <span style="color:#DD0000;"></span>$power<span style="color:#0000BB;"></span> makes it special.\n"<span style="color:#DD0000;"></span>;<span style="color:#007700;"></span>l

nl2br():

Insert HTML newline mark before all new lines in the stringl

array_rand():

Randomly take out one or more units from the arrayl

count ():

Calculate the number of units in the array or the number of attributes in the objectl

reset():

Point the internal pointer of the array to the first unitRelated recommendations:

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