Set - 2

Question 1 :

Would I use print "$a dollars" or "{$a} dollars" to print out the amount of dollars in this example?

Answer :

In this example it wouldn't matter, since the variable is all by itself, but if you were to print something like "{$a},000,000 mln dollars", then you definitely need to use the braces.


Question 2 :

What are the different tables present in MySQL? Which type of table is generated when we are creating a table in the following syntax: create table employee(eno int(2),ename varchar(10))?

Answer :

Total 5 types of tables we can create
1. MyISAM
2. Heap
3. Merge
4. INNO DB
5. ISAM
MyISAM is the default storage engine as of MySQL 3.23. When you fire the above create query MySQL will create a MyISAM table.


Question 3 :

How To Create a Table? 

Answer :

If you want to create a table, you can run the CREATE TABLE statement as shown in the following sample script: 

include "mysql_connection.php";

$sql = "CREATE TABLE Tech_links ("
. " id INTEGER NOT NULL" 
. ", url VARCHAR(80) NOT NULL"
. ", notes VARCHAR(1024)"
. ", counts INTEGER"
. ", time TIMESTAMP DEFAULT sysdate()"
. ")";
if (mysql_query($sql, $con)) {
print("Table Tech_links created.\n");
} else {
print("Table creation failed.\n");
}

mysql_close($con);

Remember that mysql_query() returns TRUE/FALSE on CREATE statements. If you run this script, you will get something like this: 
Table Tech_links created.


Question 4 :

How can we encrypt the username and password using PHP?

Answer :

Answer1
You can encrypt a password with the following

Mysql>SET PASSWORD=PASSWORD("Password"); 

Answer2
You can use the MySQL PASSWORD() function to encrypt username and password. For example,

INSERT into user (password, ...) VALUES (PASSWORD($password")), ...);

 


Question 5 :

How do you pass a variable by value?

Answer :

Just like in C++, put an ampersand in front of it, like $a = &$b


Question 6 :

What is the functionality of the functions STRSTR() and STRISTR()?

Answer :

string strstr ( string haystack, string needle ) returns part of haystack string from the first occurrence of needle to the end of haystack. This function is case-sensitive. 
stristr() is idential to strstr() except that it is case insensitive.


Question 7 :

When are you supposed to use endif to end the conditional statement?

Answer :

When the original if was followed by : and then the code block without braces.


Question 8 :

How can we send mail using JavaScript? 

Answer :

No. There is no way to send emails directly using JavaScript. 
But you can use JavaScript to execute a client side email program send the email using the "mailto" code. Here is an example:

function myfunction(form){
	tdata=document.myform.tbox1.value;
	location="mailto:mailid@domain.com?subject=...";
	return true;
}

 


Question 9 :

What is the functionality of the function strstr and stristr?

Answer :

strstr() returns part of a given string from the first occurrence of a given substring to the end of the string. For example: strstr("user@example.com","@") will return "@example.com".
stristr() is idential to strstr() except that it is case insensitive.


Question 10 :

What is the difference between ereg_replace() and eregi_replace()?

Answer :

eregi_replace() function is identical to ereg_replace() except that it ignores case distinction when matching alphabetic characters.


Question 11 :

How do I find out the number of parameters passed into function9. ?

Answer :

func_num_args() function returns the number of parameters passed in.


Question 12 :

What is the purpose of the following files having extensions: frm, myd, and myi? What these files contain?

Answer :

In MySQL, the default table type is MyISAM.
Each MyISAM table is stored on disk in three files. The files have names that begin with the table name and have an extension to indicate the file type.

The '.frm' file stores the table definition.
The data file has a '.MYD' (MYData) extension.
The index file has a '.MYI' (MYIndex) extension


Question 13 :

If the variable $a is equal to 5 and variable $b is equal to character a, what's the value of $$b?

Answer :

100, it's a reference to existing variable.


Question 14 :

How To Protect Special Characters in Query String? 
If you want to include special characters like spaces in the query string, you need to protect them by applying the urlencode() translation function. The script below shows how to use urlencode():

Answer :

print("<html>");
print("<p>Please click the links below"
." to submit comments about TECHPreparation.com:</p>");
$comment = 'I want to say: "It\'s a good site! :->"';
$comment = urlencode($comment);
print("<p>"
."<a href=\"processing_forms.php?name=Guest&comment=$comment\">"
."It's an excellent site!</a></p>");
$comment = 'This visitor said: "It\'s an average site! :-("';
$comment = urlencode($comment);
print("<p>"
.'<a href="processing_forms.php?'.$comment.'">'
."It's an average site.</a></p>");
print("</html>");

 


Question 15 :

Are objects passed by value or by reference?

Answer :

Everything is passed by value.