PHP Global variables:
Get & Post methods:
data can be sent to Body no one can see the data. (secure and mostly used).
$_POST[]: both post and get variables extracts the form fields into variables and values
$_GET[]: used send data via URL or http header. (security issues anyone can see the data)
$_REQUEST[]: it accepts both get and post method in form fields.
<form method=”POST” action=”action.php” name=return false validate()/>
Name: input type=”text” name=”name”/>
email: input type=”text” name=”email”/>
Mobile: Input type=”text” name=”mobile” />
Password: input tyepe=”text” name=”password”/>
<input type=”submit” value=”display text” />
</form>
in the above Name values (name,email,mobile,passwords) treats as Variables. and user entered inputs are treats as values.
this can be extracted by extract(S_Post[form])
Onclick form we hae set return false to validate details by cilentside scripts like js,jquery etc
server-side validation:
isset(): to know it contains value or not
empty() to check variable null or not.
Query strings: also known as “?”, using this we can pass keys and values via URL. using get method.
Connecting database
$dbconnection= Mysqli_connect(“localhost or remote”,”dbuser”,”password or empty”, “databasename”)
// Checking connection
if (!dbconnection) {
die(“Notconnect ” . mysqli_connect_error()); //here conactinating stings with mysql error fucntion to display errors.
}
mysqli_select_db(“databasename”)
- Warning: mysqli_select_db() expects exactly 2 parameters, 1 given
Error mysqli_select_db() should have 2 parameters, the connection link and the database name –
mysqli_select_db($dbconnection, ‘databaename‘) or die(mysqli_error($con));
Mysqli_query
- error :Warning: mysqli_query() expects at least 2 parameters, 1 given
$query = mysqli_query($dbconnection, “SQL query“);
Mysqli vs MySQL_connect”
mysqli is improved version of MySQL available from PHP 7. MySQL extension works up to PHP 5.6.
INSET query:
“Inset into table name (column1, column2, column3,) values (val1, val2, val3)”;
Arrays:
Associative array: in the form keys and value
ex: $form = array(“name”=>”alebert”, “email”=>”g@gmail.com”, “mobile”=>”000000000”);
Index array: $values = array(“1”, “2”, “3”);
$values[0] = “1”;
$values[1] = “2”;
$values[2] = “3”;
Multidimensional array:
WordPress & Php 7 compatibility and issues
Please Upgrade php5.6 to PHP 7.1 which uses less ram and faster performance.
RAM consume different 40MB with PHP 5.6 and php7.xx using 4-10GB ram hard. all themes and WordPress core also compatible with PHP 7 upgrade and save resources billing. also, give better speed for the user.
diffrence among =, ===, and ===.
x = 1 //x now equals 1
true == 1 //does the boolean value of true equal 1? (True) //not strict
true === 1 //does the boolean value of true equal 1? (False) //strict