Intel PHP Most Frequently Asked Interview Questions

Intel PHP Most Frequently Asked Latest Interview Questions Answers

How To Convert Strings To Upper Or Lower Cases?

Converting strings to upper or lower cases are easy. Just use strtoupper() or strtolower() functions. Here is a PHP script on how to use them:
<?php
$string = "PHP string functions are easy to use.";
$lower = strtolower($string);
$upper = strtoupper($string);
print("$lower\n");
print("$upper\n");
print("\n");
?>
This script will print:
php string functions are easy to use.
PHP STRING FUNCTIONS ARE EASY TO USE.

How To Convert The First Character To Upper Case?

If you are processing an article, you may want to capitalize the first character of a sentence by using the ucfirst() function. You may also want to capitalize the first character of every words for the article title by using the ucwords() function. Here is a PHP script on how to use ucfirst() and ucwords():
<?php
$string = "php string functions are easy to use.";
$sentence = ucfirst($string);
$title = ucwords($string);
print("$sentence\n");
print("$title\n");
print("\n");
?>
This script will print:
Php string functions are easy to use.
Php String Functions Are Easy To Use.

Intel PHP Most Frequently Asked Latest Interview Questions Answers

How To Convert Strings In Hex Format?

If you want convert a string into hex format, you can use the bin2hex() function. Here is a PHP script on how to use bin2hex():
<?php
$string = "Hello\tworld!\n";
print($string."\n");
print(bin2hex($string)."\n");
?>
This script will print:
Hello world!
48656c6c6f09776f726c64210a

How To Generate A Character From An Ascii Value?

If you want to generate characters from ASCII values, you can use the chr() function.
chr() takes the ASCII value in decimal format and returns the character represented by the ASCII value. chr() complements ord(). Here is a PHP script on how to use chr():
<?php
print(chr(72).chr(101).chr(108).chr(108).chr(111)."\n");
print(ord("H")."\n");
?>
This script will print:
Hello
72

How To Convert A Character To An Ascii Value?

If you want to convert characters to ASCII values, you can use the ord() function, which takes the first charcter of the specified string, and returns its ASCII value in decimal format. ord() complements chr(). Here is a PHP script on how to use ord():
<?php
print(ord("Hello")."\n");
print(chr(72)."\n");
?>
This script will print:
72
H

How Values In Arrays Are Indexed?
Values in an array are all indexed their corresponding keys. Because we can use either an integer or a string as a key in an array, we can divide arrays into 3 categories:

Numerical Array - All keys are sequential integers.
Associative Array - All keys are strings.
Mixed Array - Some keys are integers, some keys are strings.

How The Values Are Ordered In An Array?
PHP says that an array is an ordered map. But how the values are ordered in an array?
The answer is simple. Values are stored in the same order as they are inserted like a queue. If you want to reorder them differently, you need to use a sort function. Here is a PHP script show you the order of array values:
<?php
$mixed = array();
$mixed["Two"] = "Java";
$mixed["3"] = "C+";
$mixed["Zero"] = "PHP";
$mixed[1] = "Perl";
$mixed[""] = "Basic";
$mixed[] = "Pascal";
$mixed[] = "FORTRAN";
$mixed["Two"] = "";
unset($mixed[4]);
print("Order of array values:\n");
print_r($mixed);
?>
This script will print:
Order of array values:
Array
(
[Two] =>
[3] => C+
[Zero] => PHP
[1] => Perl
[] => Basic
[5] => FORTRAN
)

How To Get The Total Number Of Values In An Array?
You can get the total number of values in an array by using the count() function. Here is a PHP example script:
<?php
$array = array("PHP", "Perl", "Java");
print_r("Size 1: ".count($array)."\n");
$array = array();
print_r("Size 2: ".count($array)."\n");
?>
This script will print:
Size 1: 3
Size 2: 0
Note that count() has an alias called sizeof().

How To Find A Specific Value In An Array?

There are two functions can be used to test if a value is defined in an array or not:

array_search($value, $array) - Returns the first key of the matching value in the array, if found. Otherwise, it returns false.
in_array($value, $array) - Returns true if the $value is defined in $array.
Here is a PHP script on how to use arrary_search():

<?php
$array = array("Perl", "PHP", "Java", "PHP");
print("Search 1: ".array_search("PHP",$array)."n");
print("Search 2: ".array_search("Perl",$array)."n");
print("Search 3: ".array_search("C#",$array)."n");
print("n");
?>
This script will print:

Search 1: 1
Search 2: 0
Search 3:

How To Merge Values Of Two Arrays Into A Single Array?
You can use the array_merge() function to merge two arrays into a single array.
array_merge() appends all pairs of keys and values of the second array to the end of the first array. Here is a PHP script on how to use array_merge():
<?php
$lang = array("Perl", "PHP", "Java",);
$os = array("i"=>"Windows", "ii"=>"Unix", "iii"=>"Mac");
$mixed = array_merge($lang, $os);
print("Merged:\n");
print_r($mixed);
?>
This script will print:
Merged:
Array
(
[0] => Perl
[1] => PHP
[2] => Java
[i] => Windows
[ii] => Unix
[iii] => Mac
)

How To Randomly Retrieve A Value From An Array?
If you have a list of favorite greeting messages, and want to randomly select one of them to be used in an email, you can use the array_rand() function. Here is a PHP example script:
<?php
$array = array("Hello!", "Hi!", "Allo!", "Hallo!", "Coucou!");
$key = array_rand($array);
print("Random greeting: ".$array[$key]."\n");
?>
This script will print:
Random greeting: Coucou!

Can You Define An Argument As A Reference Type?

You can define an argument as a reference type in the function definition. This will automatically convert the calling arguments into references. Here is a PHP script on how to define an argument as a reference type:
<?php
function ref_swap(&$a, &$b) {
$t = $a;
$a = $b;
$b = $t;
}
$x = "PHP";
$y = "JSP";
print("Before swapping: $x, $y\n");
ref_swap($x, $y);
print("After swapping: $x, $y\n");
?>
This script will print:
Before swapping: PHP, JSP
After swapping: JSP, PHP

Can You Pass An Array Into A Function?
You can pass an array into a function in the same as a normal variable. No special syntax needed. Here is a PHP script on how to pass an array to a function:
<?php
function average($array) {
$sum = array_sum($array);
$count = count($array);
return $sum/$count;
}
$numbers = array(5, 7, 6, 2, 1, 3, 4, 2);
print("Average: ".average($numbers)."\n");
?>
This script will print:
Average: 3.75

How Arrays Are Passed Through Arguments?
Like a normal variable, an array is passed through an argument by value, not by reference. That means when an array is passed as an argument, a copy of the array will be passed into the function. Modipickzyng that copy inside the function will not impact the original copy. Here is a PHP script on passing arrays by values:
<?php
function shrink($array) {
array_splice($array,1);
}
$numbers = array(5, 7, 6, 2, 1, 3, 4, 2);
print("Before shrinking: ".join(",",$numbers)."\n");
shrink($numbers);
print("After shrinking: ".join(",",$numbers)."\n");
?>
This script will print:
Before shrinking: 5,7,6,2,1,3,4,2
After shrinking: 5,7,6,2,1,3,4,2
As you can see, original variables were not affected.

Can You Define An Array Argument As A Reference Type?
You can define an array argument as a reference type in the function definition. This will automatically convert the calling arguments into references. Here is a PHP script on how to define an array argument as a reference type:
<?php
function ref_shrink(&$array) {
array_splice($array,1);
}
$numbers = array(5, 7, 6, 2, 1, 3, 4, 2);
print("Before shrinking: ".join(",",$numbers)."\n");
ref_shrink($numbers);
print("After shrinking: ".join(",",$numbers)."\n");
?>
This script will print:
BBefore shrinking: 5,7,6,2,1,3,4,2
After shrinking: 5

What Is The Scope Of A Variable Defined In A Function?
The scope of a local variable defined in a function is limited with that function. Once the function is ended, its local variables are also removed. So you can not access any local variable outside its defining function. Here is a PHP script on the scope of local variables in a function:
<?php
?>
function myPassword() {
$password = "U8FIE8W0";
print("Defined inside the function? ". isset($password)."\n");
}
myPassword();
print("Defined outside the function? ". isset($password)."\n");
?>
This script will print:
Defined inside the function? 1
Defined outside the function?

How To Pad An Array With The Same Value Multiple Times?

If you want to add the same value multiple times to the end or beginning of an array, you can use the array_pad($array, $new_size, $value) function. If the second argument, $new_size, is positive, it will pad to the end of the array. If negative, it will pad to the beginning of the array. If the absolute value of $new_size if not greater than the current size of the array, no padding takes place. Here is a PHP script on how to use array_pad():
<?php
$array = array("Zero"=>"PHP", "One"=>"Perl", "Two"=>"Java");
$array = array_pad($array, 6, ">>");
$array = array_pad($array, -8, "---");
print("Padded:\n");
print(join(",", array_values($array)));
print("\n");
?>
This script will print:
Padded:
---,---,PHP,Perl,Java,>>,>>,>>

How To Join Multiple Strings Stored In An Array Into A Single String?

If you multiple strings stored in an array, you can join them together into a single string with a given delimiter by using the implode() function. Here is a PHP script on how to use implode():
<?php
$date = array('01', '01', '2006');
$keys = array('php', 'string', 'function');
print("A formated date: ".implode("/",$date)."\n");
print("A keyword list: ".implode(", ",$keys)."\n");
?>
This script will print:
A formated date: 01/01/2006
A keyword list: php, string, function

How To Define A User Function?

You can define a user function anywhere in a PHP script using the function statement like this: "function name() {...}". Here is a PHP script example on how to define a user function:
<?php
function msg() {
print("Hello world!\n");
}
msg();
?>
This script will print:
Hello world!

How To Invoke A User Function?

You can invoke a function by entering the function name followed by a pair of parentheses. If needed, function arguments can be specified as a list of expressions enclosed in parentheses. Here is a PHP script example on how to invoke a user function:
<?php
function hello($f) {
print("Hello $f!\n");
}
hello("Bob");
?>
This script will print:
Hello Bob!

How To Return A Value Back To The Function Caller?

You can return a value to the function caller by using the "return $value" statement. Execution control will be transferred to the caller immediately after the return statement. If there are other statements in the function after the return statement, they will not be executed. Here is a PHP script example on how to return values:
<?php
function getYear() {
$year = date("Y");
return $year;
}
print("This year is: ".getYear()."\n");
?>
This script will print:
This year is: 2018.