


Summary based on PHP commonly used strings (to be continued)_PHP tutorial
1. Split and merge
implode:
echo implode(",", array('lastname', 'email', 'phone'));//Convert array to string
explode:
print_r(explode(",", 'lastname,email,phone'));//Convert string into array
split:
print_r(split( "[/.-]","2008-9.12"));//Cut into an array with any symbol of / or . or -
str_split:
print_r(str_split("Hello Friend", 1));//Split the string
preg_split:
//Regular split
//$ops = preg_split("{[+*/-]}","3+ 5*9/2");
//print_r($ops);//Return: Array ( [0] => 3 [1] => 5 [2] => 9 [3] = > 2)
http_build_query:
//Generate the request string after url-encoded
$data = array('localhost'=>'aa',
'user' =>'bb',
'password'=>'cc');
echo http_build_query($data);//Return: localhost=aa&user=bb&password=cc
strtok:
//Cut the string into small segments
$string = "This istan examplenstring";
echo strtok($string,"nt");//Return: This is
echo '';
echo strtok("nt"); //When returning for the second time: an example
echo '
';
echo strtok("nt"); //When Return for the third time: string
2. Find and replace
Many of the strings are r: take the last one, i: case-insensitive
echo $pos = strpos( 'abcdef abcdaef', 'a'); // The first occurrence of the letter a, case sensitive
echo $pos = strrpos('abcdef abcdeaf', 'a'); // The last occurrence of the letter a position, case-sensitive
stripos: case-insensitive
strripos: case-insensitive
echo strstr('user@exa@mple.com', '@');//Return: @ exa@mple.com
stristr: case-insensitive
echo strchr('user@exa@mple.com', '@');//Return: @exa@mple.com
strrchr: Then return: @mple.com,
preg_grep:
//Return the array unit matching the pattern
$food = preg_grep("/^p/",array("apple"," orange","pip","banana"));
print_r($food); //Return: Array ( [2] => pip )
strtr:
//With Replace the found string with the specified array
$arr = array("www"=>"ftp","yahoo"=>"baidu");
echo strtr("www.yahoo.com" ,$arr);//Return: ftp.baidu.com
echo strtr("www.yahoo.com","wo","sx");//Return: sss.yahxx.cxm translation string Replace all w with s and replace all o with x
strspn:
//Find the length of the first part of the comparison
echo strspn("abcdefg","1234567890 ");//Return: 0
//Find the length of the initial part that is not matched
echo strcspn("abcdefg","1234567890");//Return: 7
3. Regular
preg_match:
//Returns the number of times pattern is matched. Either 0 times (no match) or 1 time, since preg_match() will stop searching after the first match.
if (preg_match ("/php/i", "PhP is the web scripting language of choice."))
echo "exists";
else
echo "does not exist";
preg_match_all:
//On the contrary, it will search until the end of the subject.
preg_match_all("/(?(d{3})?)?(?(1)[-s])d{3}-d{4}/x",
"Call 555-1212 or 1-800-555-1212", $phones);
print_r($phones[0]);//Get all phone numbers
ereg_replace:
//Replace URL with hyperlink
echo ereg_replace("[[:alpha:]]+://[^[:space:]]+[[:alnum:]/]",
"\0", 'This is Baidu http://www.baidu.com website.');
preg_replace:Filter
$search = array ("']*?>.*?'si", // Remove javascript
"']*?> 'si", Replace HTML entity
"'&(amp|#38);'i",
"'&(lt|#60);'i",
"'&(gt|#62); 'i",
"'&(nbsp|#160);'i",
"'&(iexcl|#161);'i",
"'&(cent|#162) ;'i",
"'&(pound|#163);'i",
"'&(copy|#169);'i",
"'(d+); 'e"); // Run as PHP code
$replace = array ("",
"",
"\1",
""",
"&",
"">",
" ",
chr(161),
chr(162),
chr(163),
chr (169),
"chr(\1)");
echo $text = preg_replace ($search, $replace, 'test<script>alert("adfasdf" );</script>');
preg_quote:
//Escape regular expression characters, add each one to conform to the regular expression.
echo preg_quote('$40 for a g3/400','/');//Return: $40 for a g3/400
sql_regcase:
//Generate size-insensitive Matching regular expression
echo sql_regcase("Foo-bar.a"); //Return: [Ff][Oo][Oo]-[Bb][Aa][Rr].[Aa]
4.URL encoding processing function
urlencode:
echo $str = urlencode('http://www.baidu.com?key=Baidu');/ /Encoding
echo urldecode($str);//Decoding
rawurlencode:
//The sequence of percent sign (%) followed by two hexadecimal numbers will be replaced with the original Meaning character
//Note: rawurldecode() will not decode the plus sign ('+') into a space, but urldecode() can.
echo $str = rawurlencode('http://www.baidu.com?key=Baidu');//Encoding
echo rawurldecode($str);
parse_url:
//Parse the URL and return its components
print_r(parse_url("http://username:password@hostname/path?arg=value#anchor"));
parse_str:
/ / is to parse the URL into variables
$str = "id=1&name=2";
parse_str($str);
echo $name;
//When there is a second parameter, put The value is stored in the array
$str = "id=1&name=2";
parse_str($str,$array);
print_r($array);
5 .Time function
mktime:
//Convert date to timestamp
echo time()-mktime(0,0,0,9,17,2008);//Return: current The time is different from September 17, 2008.
echo date('Y-m-d H:i:s');//The current date and time
getdate:
//Get date/time information
print_r(getdate(time( )));
6. Compare
similar_text:
//Compare the similarity of two strings
$a = "Hellohhh6";
$b = "hello3hh";
echo similar_text($a,$b);//Return: 6 Compare how many identical characters there are in the corresponding positions
echo "
";
similar_text($a, $b,$similar);
echo $similar."%"; //Output the percentage of identical characters
soundex:
//Compare the pronunciation of two words
$a = "ddHello6";
$b = "hello3";
echo soundex($a)."
";
echo soundex($b)."
";
if(soundex($a)==soundex($b)) echo "same pronunciation";else echo 'different';
strnatcmp():
//Character processing according to natural sorting method String comparison
$arr = array("a1.jpg","a2.jpg","a3.jpg","a4.jpg");
$max = $arr[0];
for($i=0;$i
if(strnatcmp($arr[$i],$max)>0)
$max = $arr[$i];
}
echo $max;//Return: a4.jpg
strcmp:
//Case-sensitive, string comparison by bytes, When the first string is greater than the second string, return: 1, equal to return: 0, less than return: -1
echo strcmp('abc','Abc');
strcasecmp:
/ /Return the difference between two strings
echo strcasecmp('wbc','bbc'); //Return: 21
strncmp:
//Specify the number of characters for string comparison, this The function is similar to , except that you can specify the number of characters in the string to be compared. If any string is shorter than len, the length of that string will be used for comparison
echo strncmp("adrdvark","aardwolf",4); //Return: 1
7. Sort
sort:
//Rearrange the values of the array from a-z
$a = array("1","s","3","n" ,"5");//Return: 1,3,5,n,s
sort($a);//Sort print_r($a);
8 .Other
str_pad:
//Padding the string to the specified length, pad_type can be STR_PAD_RIGHT, STR_PAD_LEFT or STR_PAD_BOTH
echo str_pad("www.yahoo.com",17,"_ ",STR_PAD_BOTH);//String filling function__www.yahoo.com__
strlen("aaa");//Finding the length of the array returns: 3
strrev();//Reversal of string
strtolower();//Convert to lowercase
strtoupper();//Convert to uppercase
str_replace() replaces the string, case-sensitive str_ireplace() not case-sensitive
ucfirst( );//Convert the first letter to uppercase
ucwords();//Convert the first letter of each word to uppercase
echo join("&",array('wo', ' men', 'shi'));//The concatenation of strings returns: wo&men&shi is concatenated with &
count_chars:
//Returns the information of the characters used in the string
print_r(count_chars("Hellohhh6",0));//Returns the number of times each byte value (0~255) appears in the string as an array of values. 0 lists all. 1Only list the occurrences greater than 0. 2 only lists those whose occurrence count is equal to 0. 3Returns a string consisting of the byte values used. Such as: 6Hehlo.4Return a string composed of unused byte values
str_replace:
str_replace("yahoo","baidu","www.yahoo.com");
$c = "www.yahoo" .com";
$arr = array("yahoo","com");
echo str_replace($arr,"baidu",$c);//Return: www.baidu.baidu
$c = "www.yahoo.com";
$arr1 = array("www","yahoo","com");
$arr2 = array("ftp","baidu" ,"net");
echo str_replace($arr1,$arr2,$c);//Return: ftp.baidu.net
substr($a,2,2);//Get Substring
echo substr_count("This is a test", "is");//Count the number of occurrences of substring
substr_replace();//Replace substring
$url = "http://localhost/zheng_ze_biao_da/youxiang.php";
echo substr($url,strrpos($url,"/")+1);//Return: youxiang.php is used to return File name
str_word_count:
$a = "I/ love/ you/";
echo str_word_count($a);//Return: 3 Count the number of words in the string
print_r(str_word_count($a,1));//Return: Array ( [0] => I [1] => love [2] => you )
//print_r(str_word_count($ a,2));//Return: Array ( [0] => I [3] => love [9] => you )
//print_r(str_word_count($a,1,"/ "));Return: Array ( [0] => I/ [1] => love/ [2] => you/ ) Here the "/" is ignored

In PHP, trait is suitable for situations where method reuse is required but not suitable for inheritance. 1) Trait allows multiplexing methods in classes to avoid multiple inheritance complexity. 2) When using trait, you need to pay attention to method conflicts, which can be resolved through the alternative and as keywords. 3) Overuse of trait should be avoided and its single responsibility should be maintained to optimize performance and improve code maintainability.

Dependency Injection Container (DIC) is a tool that manages and provides object dependencies for use in PHP projects. The main benefits of DIC include: 1. Decoupling, making components independent, and the code is easy to maintain and test; 2. Flexibility, easy to replace or modify dependencies; 3. Testability, convenient for injecting mock objects for unit testing.

SplFixedArray is a fixed-size array in PHP, suitable for scenarios where high performance and low memory usage are required. 1) It needs to specify the size when creating to avoid the overhead caused by dynamic adjustment. 2) Based on C language array, directly operates memory and fast access speed. 3) Suitable for large-scale data processing and memory-sensitive environments, but it needs to be used with caution because its size is fixed.

PHP handles file uploads through the $\_FILES variable. The methods to ensure security include: 1. Check upload errors, 2. Verify file type and size, 3. Prevent file overwriting, 4. Move files to a permanent storage location.

In JavaScript, you can use NullCoalescingOperator(??) and NullCoalescingAssignmentOperator(??=). 1.??Returns the first non-null or non-undefined operand. 2.??= Assign the variable to the value of the right operand, but only if the variable is null or undefined. These operators simplify code logic, improve readability and performance.

CSP is important because it can prevent XSS attacks and limit resource loading, improving website security. 1.CSP is part of HTTP response headers, limiting malicious behavior through strict policies. 2. The basic usage is to only allow loading resources from the same origin. 3. Advanced usage can set more fine-grained strategies, such as allowing specific domain names to load scripts and styles. 4. Use Content-Security-Policy-Report-Only header to debug and optimize CSP policies.

HTTP request methods include GET, POST, PUT and DELETE, which are used to obtain, submit, update and delete resources respectively. 1. The GET method is used to obtain resources and is suitable for read operations. 2. The POST method is used to submit data and is often used to create new resources. 3. The PUT method is used to update resources and is suitable for complete updates. 4. The DELETE method is used to delete resources and is suitable for deletion operations.

HTTPS is a protocol that adds a security layer on the basis of HTTP, which mainly protects user privacy and data security through encrypted data. Its working principles include TLS handshake, certificate verification and encrypted communication. When implementing HTTPS, you need to pay attention to certificate management, performance impact and mixed content issues.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

Notepad++7.3.1
Easy-to-use and free code editor

Dreamweaver CS6
Visual web development tools

Atom editor mac version download
The most popular open source editor

SublimeText3 Chinese version
Chinese version, very easy to use