Which is the correct method for defining a function in PHP

Which is the correct method for defining a function in PHP

• function myFunction($arg_n) { return $retval; }
• Function myFunction(p1) myFunction = (p1 - 32) End Function
• int myFunction(int p1) { return p1; }
• function myFunction(p1, p2) { return p1 * p2; } 

 

EXPLANATION

Its very easy to create your own PHP function. Suppose you want to create a PHP function which will simply write a simple message on your browser when you will call it. Following example creates a function called writeMessage() and then calls it just after creating it.
Note that while creating a function its name should start with keyword function and all the PHP code should be put inside { and } braces as shown in the following example below −

<?php
    /* Defining a PHP Function */
    function writeMessage() {
    echo "You are really a nice person, Have a nice time!";
    }
         
    /* Calling a PHP Function */
    writeMessage();
?>

For more information check out: http://php.net/manual/en/functions.user-defined.phpThe other answers and their language is below:
function myFunction(p1, p2) { return p1 * p2; } is JavaScript
Function myFunction(p1) myFunction = (p1 - 32) End Function is VBScript
int myFunction(int p1) { return p1; } is C

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Which of these is NOT a PHP class?

Which of these is NOT a PHP class?

• PDO
• XMLReader
• ErrorLog
• DateTime 

 

EXPLANATION

"ErrorLog" is the correct answer.  PHP has a function called "error_log", but it returns true/false and there is no object-oriented version like there is with some of the other classes.
PDO is a PHP extension for working with databases. XMLReader and DateTime are also classes, though they both have procedural versions too.

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In PHP scripting, which expression will output $somestring to the browser, only if it contains a colon?

In PHP scripting, which expression will output $somestring to the browser, only if it contains a colon?

• if (strpos($somestring,":")!==false) echo $somestring ;
• if (strpos($somestring,":")==true) echo $somestring ;
• if (strpos($somestring,":")!=false) echo $somestring ;
• if (strpos($somestring,":")=true) echo $somestring ;             

EXPLANATION

The correct test is "!==false"
The strpos() function finds the position of the first occurrence of a string inside another string. In this example, it looks for the numeric position of the first occurrence of a colon if one is present, or a boolean false value if none is found.
PHP strings are zero-indexed, so a string starting with colon (:) will return a numeric zero from strpos(). However, as in most scripting languages, the variables are not strongly typed, zero and false being equivalent in logic tests.
Thus, a string starting with a colon would cause the zero output of strpos() to be interpreted as 'Not found' and nothing would be output to the browser.
The workaround is to use a literal boolean test, which is expressed with '===' or '!==' for equality or inequality as appropriate.
The '===' test cannot be used here, because a colon's presence is returned as an integer value, which is not literally a boolean value. Thus doing so would result in no output, ever. (False or an integer are never literally equal to true.)
The correct approach is therefore to ask, 'Is the value returned by strpos() NOT LITERALLY a BOOLEAN FALSE' -which yields true for colon present anywhere including first character, false for no colon. (Also false for a null string)
Incidentally, BASIC-like languages index strings from one, so the issue does not arise. Javascript indexes strings from zero, but search functions typically return -1 as the 'not found' response.
The lowdown:
if (strpos($somestring,":")!==false) echo $somestring ; // Yay! It worked. :)
if (strpos($somestring,":")=true) echo $somestring ;     // This is a syntax error.
if (strpos($somestring,":")===true) echo $somestring ; // Never outputs anything.
if (strpos($somestring,":")!=false) echo $somestring ;   // Fails if the colon is first char, otherwise works.
if (strpos($somestring,":")==true) echo $somestring ;   // Fails if the colon is first char, otherwise works.

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Which of these is NOT a PHP class?

Which of these is NOT a PHP class?

• ErrorLog
• DateTime
• PDO
• XMLReader 

 

EXPLANATION

"ErrorLog" is the correct answer.  PHP has a function called "error_log", but it returns true/false and there is no object-oriented version like there is with some of the other classes.
PDO is a PHP extension for working with databases. XMLReader and DateTime are also classes, though they both have procedural versions too.

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