Basic PHP Programming Interview Questions and Answers

21 :: How To Remove the New Line Character from the End of a Text Line in PHP?

If you are using fgets() to read a line from a text file, you may want to use the chop() function to remove the new line character from the end of the line as shown in this PHP script:

<?php
$handle = fopen("/tmp/inputfile.txt", "r");
while ($line=fgets()) {
$line = chop($line);
# process $line here...
}
fclose($handle);
?>

Is This Answer Correct?    1 Yes 0 No

22 :: How To Remove Leading and Trailing Spaces from User Input Values in PHP?

If you are taking input values from users with a Web form, users may enter extra spaces at the beginning and/or the end of the input values. You should always use the trim() function to remove those extra spaces as shown in this PHP script:

<?php
$name = $_REQUEST("name");
$name = trim($name);
# $name is ready to be used...
?>

Is This Answer Correct?    1 Yes 0 No

23 :: How to Find a Substring from a Given String in PHP?

To find a substring in a given string, you can use the strpos() function. If you call strpos($haystack, $needle), it will try to find the position of the first occurrence of the $needle string in the $haystack string. If found, it will return a non-negative integer represents the position of $needle. Othewise, it will return a Boolean false. Here is a PHP script example of strpos():

<?php
$haystack1 = "2349534134345globalguideline16504381640386488129";
$haystack2 = "globalguideline234953413434516504381640386488129";
$haystack3 = "guideline234953413434516504381640386488129ggl";
$pos1 = strpos($haystack1, "globalguideline");
$pos2 = strpos($haystack2, "globalguideline");
$pos3 = strpos($haystack3, "globalguideline");
print("pos1 = ($pos1); type is " . gettype($pos1) . " ");
print("pos2 = ($pos2); type is " . gettype($pos2) . " ");
print("pos3 = ($pos3); type is " . gettype($pos3) . " ");
?>

This script will print:

pos1 = (13); type is integer
pos2 = (0); type is integer
pos3 = (); type is boolean

"pos3" shows strpos() can return a Boolean value

Is This Answer Correct?    1 Yes 0 No

24 :: What Is the Best Way to Test the strpos() Return Value in PHP?

Because strpos() could two types of values, Integer and Boolean, you need to be careful about testing the return value. The best way is to use the "Identical(===)" operator. Do not use the "Equal(==)" operator, because it does not differentiate "0" and "false". Check out this PHP script on how to use strpos():

<?php
$haystack = "needle234953413434516504381640386488129";
$pos = strpos($haystack, "needle");
if ($pos==false) {
print("Not found based (==) test ");
} else {
print("Found based (==) test ");
}
if ($pos===false) {
print("Not found based (===) test ");
} else {
print("Found based (===) test ");
}
?>

This script will print:

Not found based (==) test
Found based (===) test

Of course, (===) test is correct.

Is This Answer Correct?    0 Yes 1 No

25 :: How To Take a Substring from a Given String in PHP?

If you know the position of a substring in a given string, you can take the substring out by the substr() function. Here is a PHP script on how to use substr():

<?php
$string = "beginning";
print("Position counted from left: ".substr($string,0,5)." ");
print("Position counted form right: ".substr($string,-7,3)." ");
?>

This script will print:

Position counted from left: begin
Position counted form right: gin

substr() can take negative starting position counted from the end of the string.

Is This Answer Correct?    0 Yes 1 No