Understanding && in PHP if -clause

Question

How can you get 1 as an output from #2?

#1

I ran this code

echo validate_email ( $email );
echo validate_password ( $password );
echo validate_username ( $username );

I get

111

which means that everything is ok.

#2

I run this code

function validate ( $email, $password, $username ) {
    if (  (validate_email ( $email ) == 1)
        AND (validate_password ( $password ) == 1)
        AND (validate_username ( $username ) == 1 ) )
            return 1;
}
echo validate ($email, $password, $username );

I get nothing as an ouput.

I tried to fix the problem by changing AND to && but the same output remains. The output should be 1.

Answer 1

You get nothing as output because you are only returning 1, not actually echo-ing it. Things don't get echo-ed to the user unless you tell PHP to do so.

Example:

function test() {
    if (  (validate_email ( $email ) == 1)
        AND (validate_password ( $password ) == 1)
        AND (validate_username ( $username ) == 1 ) )
            return 1;
    else
            return 0;

echo test();

Also, here are a couple of points on if in general:

• You should probably use && instead of AND as the former is more common.

• You don't need the == 1 bit in there - 1 is always TRUE. Example:

  if ( validate_email($email) ) // correct email
  

  Instead of:

  if ( validate_email($email) == 1 ) // correct email
  

Answer 2

In the first example you echo the output of each function. In the second example you return 1 if they all equal 1.

Returning something doesn't output it to STDOUT. You need to echo it if you want that.