PHP Lesson 8 Common Functions for String Splitting

PHP Lesson 8 Common Functions for String Splitting_PHP Tutorial

WBOY

Release： 2016-07-13 10:19:49

Original

924 people have browsed it

PHP Lesson 8 Common Functions for String Splitting

Course Overview:

Through this lesson, you can perform basic operations on strings.

String knowledge points:
1. Introduction to string processing
2. Commonly used string output functions
3. Commonly used string formatting functions
4. String comparison function
5. Application of regular expressions in strings
6. Regular expression used with per1

1.pathinfo();//Return the path information of the domain name

2.parse_url();
3.parse_str(); // Used to split parameters

pathinfo();

	<?php
	$str="http://blog.csdn.net/junzaivip";
	$arr = pathinfo($str);


	echo "<pre class="code">";
	print_r($arr);
	echo "

Copy after login

"; ?>

//Split a domain name into an array

<?php
	$str="http://blog.csdn.net/junzaivip.php?id=10&name=20";
	$arr = parse_url($str);


	$query = $arr[&#39;query&#39;];




	$arr2 = explode("&",$query);


	foreach ($arr2 as $val) {


		$arr3 = explode("=", $val);
		foreach ($arr3 as $value) {
			$arr4[$arr3[0]] = $arr3[1]; 
		}
		
	}


	echo "<pre class="code">";
	print_r($arr4);
	echo "

Copy after login

"; ?>

//Same method to get

<?php
	$str="http://blog.csdn.net/junzaivip.php?id=10&name=20";
	$arr= parse_url($str);
	parse_str($arr[&#39;query&#39;],$arr4);


	echo "<pre class="code">";
	print_r($arr4);
	echo "

Copy after login

"; ?>

//Method 3

<?php
	$str="http://blog.csdn.net/junzaivip.php?id=10&name=20";
	$arr= parse_url($str);
	
	$arr2 = preg_split(&#39;/&|=/&#39;, $arr[&#39;query&#39;]);


	//echo count($arr2);


	for ($i=0; $i < count($arr2); $i++) { 
		$arr3[$arr2[$i]] = $arr2[++$i];
	}


	echo "<pre class="code">";
	print_r($arr3);
	echo "

Copy after login

"; ?>

String knowledge points:
1. Introduction to string processing
2. Commonly used string output functions
3. Commonly used string formatting functions
4. String comparison function
5. Application of regular expressions in strings
6. Regular expression used with per1

String function
echo
print
printf(); direct output
sprintf(); returns directly

String concatenation character:
. Connect with dots
print "aaaaaaaaaa";
printf("----%s--$s--",$a,$b);
%s string
%d number
%f floating point type (%.2f represents two digits after the decimal point)

sprintf(); does not output directly, returns a new variable

Commonly used string formatting functions:
1. Take out spaces and string padding function
1.ltrim(); //Remove left space
2.rtrim(); //Remove right space
3.trim(); //Remove spaces on both sides
4.str_pad();//Used to fill spaces or customize characters to a specified length
5.str_repeat();//Used to repeat the previous characters (used to make unlimited category menus)
6.strlen() //Get the string length

echo "|". str_repeat("-",5)."bb";

String case conversion function
1.strtoupper();//Convert all to uppercase
2.strtolower();//Convert all to lowercase
3.ucfirst();//Capitalize the first letter
4.ucwords(); //The first letter of each letter is capitalized

Other string formatting functions:
1.strlen();//String length
2.strrev();//String flip
3.number_format();//Number character function in format
4.md5 //md5 encrypted string, 32-bit string
5.str_shuffle(); randomly shuffles the string, the number of digits remains unchanged

String functions:
String functions associated with html:
1.nl2br(): Convert /n to br tag
2.htmlspecialchars(); Convert to entity
' " &Convert to entity
":represents entity
<:less than sign
>:Greater than sign
3.addslashes() //' "" is added in front to reduce damage to the database
4.stripslashes() //' Remove the previous ones
3.strip_tags(); Only keep certain tags and remove the tags you want to remove

Note: It is recommended to carry out three controls before inserting into the database
1.[b][/b] Only convert limited tags and do tag filtering
2.addslashes();
' "" is added in front to reduce damage to the database
3.htmlspecialchars()
' " &Convert to entities to prevent any errors in the database