Friday 11 August 2017

PHP Technical Interview Questions and Answer for 3 year experienced

PHP Technical Interview Questions and Answer for 3 year experienced

Question: What is output of below script?
var_dump(0123 == 123);
var_dump('0123' == 123);
var_dump('0123' === 123);

Output
var_dump(0123 == 123);//false
var_dump('0123' == 123); //true
var_dump('0123' === 123);//false



Question: What is output of below script?
var_dump(true and false);
var_dump(true && false);
var_dump(true || false);

Output
var_dump(true and false); //false
var_dump(true && false); //false
var_dump(true || false); //true



Question: What is output of below script?
$a1=true and false;
$a2=true && false;
$a3=true || false;

var_dump($a1);
var_dump($a2);
var_dump($a3);

Output
$a1=true and false;
$a2=true && false;
$a3=true || false;

var_dump($a1);//true
var_dump($a2);//false
var_dump($a3);//true



Question: What is output of below script?
echo  10 + "10%" + "$10";

Output
echo  10 + "10%" + "$10"; //20

Reason: First 10 is 10
Second 10 is 10
Third 10 is 0 (Because start with $)


Question: What is output of below script?
$text = 'HELLO';
$text[1] = '$';
echo $text;

Output
$text = 'HELLO';
$text[1] = '$';
echo $text;//H$LLO 


Question: What is output of below script?
$x = NULL;
var_dump($x);

Output
$x = NULL;
var_dump($x);/null


Question: Why do we use ob_start()?
Ob_start used to active the output buffering .


Question: What is a .htacces file?
.htaccess is a configuration file running on server.
Following task can be done with .htacces?
  1. URL Rewrite
  2. Website password protected.
  3. Restrict ip addresses
  4. PHP/Apache Configuration
  5. Set browser caching for Speed up application.


Question: What is the difference between compiler language and interpreted language?
Interpreted language executes line by line, if there is some error on a line it stops the execution of script. Compiler language can execute the whole script at a time and gives all the errors at a time. It does not stops the execution of script ,if there is some error on some line.


Question: What is type hinting?
Type hinting means the function specifies what type of parameters must be and if it is not of the correct type an error will occur.



Question: What will be output of following?
$x = 5;
echo $x;
echo "
"; echo $x+++$x++; echo "
"; echo $x; echo "
"; echo $x---$x--; echo "
"; echo $x;



Output
5
11
7
1
5


Question: What will be output of following?
$a = 1;
$b = 2;
echo $a,$b;


Output
12


Question: What will be output of following?
var_dump(0123 == 123);
var_dump('0123' == 123);
var_dump('0123' === 123);


Output
boolean false
boolean true
boolean false