PHP AND OR Condition with if else

Question

I have a confusion, what is wrong here? if A & B or C is set it should print yes, otherwise it should print the error message

$a = 1;
$b = 2;
$c = null;

if ((is_null($a) && is_null($b)) || is_null($c)) {
    echo 'A and B or C cannot be blank.';
}
else
    echo 'yes';

here i have A & B assigned but still its printing 'A and B or C cannot be blank.'

To Make it more clear. A= Firstname, B=lastName, C=Email. so user should either give first name and last name otherwise email.

The logic is currently: if $a AND $b is NULL, OR if $c is NULL, enter. It's doing what it's suppose to. — Epodax
– Epodax, Commented Oct 1, 2015 at 10:06
@Epodax but in my acse $a AND $b are set to 1 and 2. they are not null. — dev1234
– dev1234, Commented Oct 1, 2015 at 10:10
The entire if clause is read/checked, not just the first part. — Epodax
– Epodax, Commented Oct 1, 2015 at 10:12

Al Amin Chayan · Accepted Answer · 2015-10-01 11:09:59Z

6

You should do this following way:

$a = 1;
$b = 2;
$c = null;

if ((!is_null($a) && !is_null($b)) || !is_null($c)) {
    echo 'yes';
}
else
{
    echo 'A and B or C cannot be blank.';
}

Update:

if ((is_null($a) || is_null($b)) && is_null($c)) {
    echo 'A and B or C cannot be blank.';
}

edited Oct 1, 2015 at 11:09

answered Oct 1, 2015 at 10:04

Al Amin Chayan

2,5004 gold badges26 silver badges43 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

dev1234 Over a year ago

its failing when i assigned these. $a = null; $b = 1; $c = 3; i have defined c, so it should say yes but its saying the error.

dev1234 Over a year ago

can u write this using only if without else. if condition then echo error message. thats all.

Hiltje · Accepted Answer · 2015-10-01 10:11:53Z

2

You have A&B assigned but the if condition says that A&B or C must be true to print "A and B or C cannot be blank". The A&B part are false at the moment you assigned value to them. This means if( false (A&B assigned) or true (C is not assigned)) which will lead to true and thus print "A and B or C cannot be blank"

answered Oct 1, 2015 at 10:11

Hiltje

1401 silver badge5 bronze badges

1 Comment

Hiltje Over a year ago

If I were you I would switch what you want to echo. In the if statement echo "yes" and in the else statement echo "A and B or C cannot be blank". Second option is to change all is_null into !is_null and don't switch what is echoed.

Jatin Seth · Accepted Answer · 2015-10-01 10:12:57Z

2

    $a = 1;
    $b = 2;
    $c = null;

    if ((is_null($a) && is_null($b)) || is_null($c)) {
        echo 'yes';
    }
   else{    
     echo 'A and B or C cannot be blank.';
    }

answered Oct 1, 2015 at 10:12

Jatin Seth

3121 gold badge4 silver badges19 bronze badges

Comments

jeromegamez · Accepted Answer · 2015-10-01 10:39:55Z

1

In your original post, you wrote

if A & B or C is set it should print yes, otherwise it should print the error message

but you are actually testing for unset variables.

A solution closer to your assertion (and also more readable) would be to write the code like this:

if (($a && $b) || $c) {
    echo 'yes';
} else {
    echo 'A and B or C cannot be blank.';
}

The brackets around $a && $b are not necessary, but help determining the expected groupings.

answered Oct 1, 2015 at 10:39

jeromegamez

3,5711 gold badge25 silver badges38 bronze badges

Comments

Ishan Shah · Accepted Answer · 2015-10-01 10:26:44Z

0

    $a = 1;
    $b = 2;
    $c = null;

    if ((empty($a) && empty($b)) || empty($c)) {
         echo 'A and B or C cannot be blank.';
    }
   else{    
      echo 'yes';
    }

answered Oct 1, 2015 at 10:26

Ishan Shah

1,6862 gold badges20 silver badges43 bronze badges

Collectives™ on Stack Overflow

PHP AND OR Condition with if else

5 Answers 5

2 Comments

1 Comment

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

2 Comments

1 Comment

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related