Interview Questions & Answers

If you have a file, and you want to read the entire file into a single string, you can use the file_get_contents() function. It opens the specified file, reads all characters in the file, and returns them in a single string.

The session support can be turned on automatically at the site level, or manually in each PHP page script:
* Turning on session support automatically at the site level: Set session.auto_start = 1 in php.ini.
* Turning on session support manually in each page script: Call session_start() function.

We can create MySQL database with the use of mysql_create_db($databaseName) to create a database.

Just run the PHP CLI (Command Line Interface) program and provide the PHP script file name as the command line argument. For example, "php myScript.php", assuming "php" is the command to invoke the CLI program.
Be aware that if your PHP script was written for the Web CGI interface, it may not execute properly in command line environment.

To store uploaded files to MySQL database, you can use the normal SELECT statement as shown below:
<?php
$con = mysql_connect("localhost", "", "");
mysql_select_db("fyi");
$error = $_FILES['fyicenter_logo']['error'];
$tmp_name = $_FILES['fyicenter_logo']['tmp_name'];
$size = $_FILES['fyicenter_logo']['size'];
$name = $_FILES['fyicenter_logo']['name'];
$type = $_FILES['fyicenter_logo']['type'];
print("
\n");
if ($error == UPLOAD_ERR_OK && $size > 0) {
$fp = fopen($tmp_name, 'r');
$content = fread($fp, $size);
fclose($fp);
$content = addslashes($content);
$sql = "INSERT INTO fyi_files (name, type, size, content)"
. " VALUES ('$name', '$type', $size, '$content')";
mysql_query($sql, $con);
print("File stored.\n");
} else {
print("Upload faield.\n");
}
print("
\n");
mysql_close($con);
?>
Note that addslashes() is used to add backslashes to special characters that need to be protected in SQL statements.

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 e.g. 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: http://www.mysamplesite.com/sample.php
The sample.php file can be used for catching the form data using $_POST
Hello <?php echo $_POST["name"]; ?>.
You are <?php echo $_POST["age"]; ?> years old!
GET EXAMPLE
Name:
Age:
On clicking submit the URL resembles to : http://www.mysamplesite.com/sample.php?name=jim&age=37
The sample.php file can be used for catching the form data using $_GET
Hello <?php echo $_GET["name"]; ?>.
You are <?php echo $_GET["age"]; ?> years old!

isset() function is used to determine if a variable is set or not. It returns true if the variable exists. If multiple parameters are supplied then isset() will return TRUE only if all of the parameters are set.
Example:
$a =”sample”;
var_dump(isset($a)); //true;