What Is a Session in PHP?

Correct Answer: The function setcookie() is used to define a cookie that is to be sent along with HTTP headers The cookie must be sent prior to any output from the script as is the protocol restriction After setting the cookies, they can be used when the next page is loaded by using $_COOKIE or $HTTP_COOKIE_VARS arrays

Correct Answer: Both GET and POST are used to collect data from a form However, when security is desired $_POST should be used When the $_ POST variable is used, all variables used are NOT displayed in the URL Also, they have no restrictions to the length of the variables GET should be used when the interaction with the form is more like a question For eg firing a query etc POST should be used more often when the interaction is more like an order or the interaction changes the state of the resource POST example:

Name: Age:

On clicking submit the URL resembles to: https://wwwmysamplesitecom/samplephp The samplephp file can be used for catching the form data using $_POST Hello
You are years old! GET EXAMPLE

Name: Age:

On clicking submit the URL resembles to : https://wwwmysamplesitecom/samplephp?name=jim&age=37 The samplephp file can be used for catching the form data using $_GET Hello
You are years old!

Correct Answer: PHP supports single level inheritance Inheriting a class would mean creating a new class with all functionality of the existing class in addition to some more The created class is called as a subclass of the parent class Parent is a keyword which we use to access members of a parent class Inheritance is usually defined by using the keyword ?Extend? $this is used a reference to the calling object Inheritance avoids redundancy of code Example: Class employee extends manager : Here Employee is a subclass of manager Echo $this->name can be used to echo variable name of the parent class

Correct Answer: Generating random passwords in PHP can be done in multiple ways depending on how much security the application demands:- Md5 function can be passed one parameter as uniqid() function which in turn generates a random number Passing the parameter as TRUE in uniqid() adds additional uniqueness

Correct Answer: A HTML form should be build before uploading the file The following HTML code is used for selecting the file that is to be uploaded The type attribute of input must be ?file?

Choose a file to upload:

At the time of executing uploaderphp, the uploaded file will be stored in a temporary storage are on the webserver An associative array $_FILES['uploadedfile']['name'] is used for uploading The ?name? is the original file that is to be uploaded Another associative array $_FILES['uploadedfile']['tmp_name'] is used for placing the uploaded file in a temporary location on the server and the file should be empty and should exist with the tmp_name The following code snippet is used for uploading the file $target_path = "uploads/"; // the target location of the file $target_path = $target_path basename( $_FILES['uploadedfile']['name']); if(move_uploaded_file($_FILES['uploadedfile']['tmp_name'], $target_path)) { echo "The file " basename( $_FILES['uploadedfile']['name']) " has been uploaded"; } else { echo ?There was an error while uploading the file?; } The function move_uploaded_file()is used to place the source file into the destination folder, which resides on the server If the uploading is successful, the message ?The file filename has been uploaded Otherwise the error message ?There was an error while uploading the file? would be displayed

Correct Answer: User names and passwords in PHP can be encrypted using md5 function MD5 function calculates the md5 hash of a string It is basically used for encryption It is also used for digital signature applications, where a large file must be "compressed" in a secure manner Example: Md5($str); Crypt() function can also be used to encrypt a string, It used MD5, DES or blow fish algorithms for encryption Syntax: Crypt(str, salt) Salt is an optional parameter used to increase the number of characters encoded, to make the encoding more secure

Correct Answer: Chmod() is used for changing permissions on a file Syntax: Chmod(file, mode) Mode here specifies the permissions as follows: The first number is always zero The second number specifies permissions for the owner The third number specifies permissions for the owner's user group The fourth number specifies permissions for everybody else Possible values (to set multiple permissions, add up the following numbers) 1 = execute permissions 2 = write permissions 4 = read permissions Example: // everything for owner, read for owner's group chmod("testtxt",0740);

Correct Answer: Opendir():- It opens the directory This function returns a directory stream on success and FALSE and an error on failure Syntax: Opendir(directory, context) Context is a set of options that can modify the behavior of a stream Example: opens sample directory $dir = opendir("directory"); Readdir(): It returns an entry from a directory handle opened by opendir() Syntax: Readdir(dir_stream) Example: $file = readdir($dir); closedir(): It closes a directory handle opened by opendir() Syntax: closedir(dir_stream) Example: $file = close($dir);

Correct Answer: Copy() makes a copy of the file It returns TRUE on success It can copy from any source to destination Move simply Moves the file to destination if the file is valid While move can move the uploaded file from temp server location to any destination on the server If filename is a valid upload file, but cannot be moved for some reason, no action will occur

Correct Answer: There is a decent page in the php manual on the subject, in short mysql_pconnect() makes a persevering association with the database which implies a SQL join that don't close when the execution of your script closes mysql_connect()provides just for the database new association while utilizing mysql_pconnect , the capacity would first attempt to locate a (relentless) connection that is as of now open with the same host, username and password On the off chance that one is found, an identifier for it will be returned as opposed to opening another connection the connection with the SQL server won't be terminated when the execution of the script ends Rather, the link will stay open for future use