PHP commonly used string functions.

Nl2br
Function: <br> of line break

<?php$str = "cat isn ' t \ n Dog"; $result = NL2BR ($STR); echo $result;/** result cat isn ' tdog*/

RTrim
Function: Clear the blank on the right

<?PHP$STR = "Hello world   "; Echo strlen ($STR). " <br> "; $result = RTrim ($STR); Echo strlen ($result);/** results 1411*/

Strip_tags
Function: Clear the HTML and PHP tags in the string

<?PHP$STR = "<font color = ' Red ' >hello world</font>"; $result = Strip_tags ($STR); echo $result;/** result Hello world*/

Strtolower
Strtoupper
Functions: Converting to uppercase and lowercase

<?php$str = "Hello world!"; $result = Strtolower ($STR); Echo $result. " <br> "; $result = Strtoupper ($STR); echo $result;/** result Hello world! HELLO world!*/

Trim
Function: Remove the leading and trailing spaces

<?php$str = "  Hello world!  "; $result = Trim ($STR); Echo $str. " <br> "; Echo $result." <br> "; Echo strlen ($STR)." <br> "; Echo strlen ($result);/** result Hello world! Hello world!1612*/

Str_ireplace
function: Replace

<?php$str = "Zhang San"; $result = Str_ireplace ("Zhang", "Li", $str); Echo $str. " <br> "Echo $result/** results Zhang Sanli san*/

Str_repeat
Function: Repeat a string multiple times

<?php$str = "Hello jiqing!"; $result = Str_repeat ($str, 4); Echo $str. " <br> "; echo $result;/** result Hello jiqing! Hello jiqing! Hello jiqing! Hello jiqing! Hello jiqing!*/

Str_replace
Function: Case-sensitive substitution

<?php$str = "Hello jiqing!"; $result 1 = str_ireplace ("Hello", "Hi", $str); Case-insensitive $RESULT2 = Str_replace ("Hello", "Hi", $str);  Case-sensitive echo $str. " <br> "echo $result 1." <br> "Echo $result 2." <br> ";/** result Hello jiqing! Hi Jiqing!hello jiqing!*/

Str_word_count
Function: Returns the number of words in a string

<?php$str = "Hello jiqing a!"; $result 1 = str_word_count ($STR);    Number of returns $RESULT2 = Str_word_count ($str, 1);  Returns the array echo $str. <br> "echo $result 1." <br> ";p Rint_r ($result 2);/** result Hello jiqing a!3array ([0] = = Hello [1] = = jiqing [2] = a) */

Strlen
Function: Returns the string length

<?php$str = "Hello jiqing a!"; $result = strlen ($STR); echo $result;/** result 15*/

Substr_count
Function: Calculates the number of a string in another string

<?php$str = "Hello jiqing, hello jim!"; $result = Substr_count ($str, "Hello"); echo $result;/** result 2*/

Substr_replace
Function: Start a replacement from a location

<?php$str = "Hello jiqing, hello jim!"; $result = Substr_replace ($str, "Zhangsan", 6); Echo $result. " <br> "; $result = Substr_replace ($str," Zhangsan ", 6,6);//replace from a location, replace several strings echo $result;/** result Hello Zhangsanhello Zhangsan, Hello jim!*/.

Substr
function: Get substring

<?php$str = "ABCdef"; $result = substr ($str, 0, 1); Starting with the No. 0, get 1 echo $result. " <br> "; $result = substr ($str, 0,-1);//Starting from No. 0, get the echo $result except for the last string." <br> "; $result = substr ($str, 2,-1);//starting from 2nd, get the echo $result except for the last string." <br> "; $result = substr ($str, -3,-1);//starting from 3, get the echo $result except for the last string." <br> "; $result = substr ($str, -3,1);//starting from 3, get the echo $result except for the last string." <br> ";/** results aabcdecdeded*/

Implode
Function: Convert an array to a string

<?php$array = Array ("6", "3"), $date = Implode ("/", $array); echo $date;/** result 2013/6/3*/

Md5
Function: MD5 encryption of strings

<?PHP$STR = "Hello World"; $result = MD5 ($STR); echo $result;/** result 3e25960a79dbc69b674cd4ec67a72c62*/

PHP commonly used string functions.