PHP Basics 1

PHP: Equivalent to a wall between the client and MySQL Apache (Apache): is the Web server software localhost: equivalent to a domain nameFirst, Wampserver

• HTTP.CONF: Used to configure Apache
• PHP.ini: Used to configure the PHP language
• My.ini: Used to configure MySQL

ii. Basic PHP statements

• Format: <?php?>
• Output: Echo
• Output system time: <?php echo Date ("y-m-d h:i:s");? >
• Variable declaration: $a = 3;
• Line break: echo "

Third, PHP "+" and JavaScript "+" Difference

• JS "+" number contains the addition and character stitching two meanings
• PHP's "+" only adds this meaning

iv. PHP Character stitching symbol-"."Example: $str 1.$str 2

• '. = ': equivalent to + =,-=, *=,/= and other symbolic usages

Five, PHP "," ", {} three differences

• Single quote ': The contents of a single quotation mark are simply strings and have no meaning
• Double quotation mark "": Content in the meaning, variables, arrays, etc. have their own meaning
• Curly braces {}: General variables in curly braces
• Note:
• echo "I am the number". $str 1. " 2 ";
• echo "I am the number {$str 1}2";
• The same output effect

Six, Value assignment

• $str 2= $str 1;
• Assign the value of $STR1 directly to $STR2

Vii. Reference Assignment

• $str 2 = $str 1
• $STR2 points to the value of $STR1, $str 1 changes, $STR 2 will change as well.

Variables of variables

• $val _1= ' Hello ';
• $ $val _1= ' world '; Turn $val_1 into a variable
• Echo $hello; --Output world
• echo ${$val _1}; --Output world

Nine, connect, create an HTML and a PHP file

• Form.html content:

• <Body>    <formAction= "get.php"Method= "Get">        <inputtype= "text"name= "User">        <inputtype= "Pass"name= "Pass">        <inputtype= "Submit">    </form></Body>

• get.php content:

• <? php     var_dump ($_get);    echo $_get[' user ';    foreach ($_get as $key = $value) {        echo $value.  ?>

10. Get and Post

• Get: Is IP-insecure and therefore unsafe
• PHP section with $_get to receive
• Post: Is protocol-safe, but relatively slow
• PHP section with $_post to receive

11. Array:Request an array: $arr =array (All-in-one);12. For Loop

• Traditional for loop: for ($i =0; $i <100; i++) {...}
• A For loop in JSON form:
• foreach ($obj as $key = = $value) {...}
• Work with each content
• foreach ($obj as $value) {...}

13, COUNT ($arr): array length14. Server Variable $_server

• This global variable contains information about the server and client configuration and the current request environment

15. Define Constants (invariant)

• Define ("PI", 3.1415926); Echo pi;     --Output 3.1415926

16. System version--php_os

• PHP version: Php_version

17. Magic Constant

• File Current line number: __line__
• Function Name: __function__

18. Delimiter

•     $str 2=<<<end    ...    --> Here The content is meaningful, meaningless characters are used as the normal character end;  It must be on the top side here.

19, GetType ($a)Determine the data type of a20, Is_int ($a)

• Determines whether a is an integral type, or returns a Boolean value of true, otherwise false. The rest .

PHP Basics 1