PHP WEB DEVELOPMENT PART - 2 PROBABLE MOST IMPORTANT INTERVIEW QUESTIONS AND ANSWERS MADE BY ME GENERALLY ASKED IN PITANGENT ANALYTICS AND TECHNOLOGY SOLUTIONS PVT. LTD. FOR FRESHERS

 PHP WEB DEVELOPMENT PART - 2 PROBABLE MOST IMPORTANT INTERVIEW QUESTIONS AND ANSWERS MADE BY ME GENERALLY ASKED IN PITANGENT ANALYTICS AND TECHNOLOGY SOLUTIONS PVT. LTD. FOR FRESHERS

Q8. What is the difference between GROUP BY and ORDER BY?

Ans: GROUP BY => GROUP BY statement can create the group with the same values and it has some aggregated functions. For ex. : MAX(), MIN(), AVG(), COUNT(), SUM().

ORDER BY => ORDER BY statement can return the value in order wise.

Q9. How to update a column using UPDATE query?

Ans: UPDATE table_name SET column_name = new_value WHERE condition;

Q10. How to center a div both vertically and horizontally?

Ans: To center a div both vertically and horizontally, we can use padding and text-align : center as well as we can use the below 5 ways:

=> display : flex method.

=> display : grid method.

=> position : absolute and transform : translate method.

=> table and table-cell method.

=> line-height method.

Q11. What are pseudo classes in CSS?

Ans: pseudo classes in CSS is a keyword added to a selector that lets you style a specific state of a selected element or elements. For ex. => :hover.

Q12. Write a program to swap two variables without using a third variable.

Ans: Arithmetic Operation =>

<?php

$a=50;

$b=100;

// $a=$a+$b=50+100=150;

$a=$a+$b;

// $b=$a-$b=150-100=50;

$b=$a-$b;

// $a=$a-$b=150-50=100;

$a=$a-$b;

echo "a=$a,<br>b=$b";

?> 

Bitwise XOR =>

<?php

$x=10;

$y=20;

$x=$x^$y;

$y=$x^$y;

$x=$x^$y;

echo "x=$x,<br>y=$y";

?>