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PHP Build a Simple PHP Application Adding a Contact Form Working with Get Variables

Posted by Colby Work
Colby Work
20,422 Points

Why does Randy use AND instead of &&?

I have taken php courses in the past, and they always use && and I have never seen "and" and "or" being used. Is there a best practice, or does it matter?

And btw, I really love this guy's style of teaching. Very informative, mellow, and easy to follow along.

Thanks!

2 Answers

Muhammad Mohsen
Muhammad Mohsen
Courses Plus Student 10,843 Points

Hi Colby,

&& & || are the equivalent to and & or

Check this out http://php.net/manual/en/language.operators.logical.php

Chi Lee
Chi Lee
3,431 Points
Chi Lee
Chi Lee
3,431 Points

I guess 'AND' and '&&' are basically the same but with different precedence

'&&' has a higher precedence comparing to 'AND'.

Problem arises when we assign (=) conditional statement to a boolean value as we have the following precedence order: '&&' > '=' > 'AND'

$a = true;
$b = false;

echo '$a && $b: ' . (int) ($a && $b) . "\n"; // 0
echo '$a and $b: ' . (int) ($a and $b). "\n"; // 0

$boolVal_1 = $a && $b; 
echo '$boolVal_1: ' . (int) $boolVal_1 . "\n" ; // 0

// Problem arises since '= ' has a high precedence than 'and'
// The below code is executed implicitly as below:
// ($boolVal_2 = $a) and $b; 
$boolVal_2 = $a and $b; 
echo '$boolVal_2: ' . (int) $boolVal_2 . "\n"; // 1 !!!

// Problem solved when we put parathesis explicitly
$boolVal_3 = ($a and $b); 
echo '$boolVal_3: ' . (int) $boolVal_3 . "\n"; // 0