Best way to write TWO if conditions

Shell Programming and Scripting
1

HI all,
In PERL, I want to know which is best practice among the two methods to write TWO IF conditions.
In first method both conditions are evaluated every time $iop is fetched. but in the second method the second condition ($iop =~ /nop/) is evaluated only if First condition is satisfied ( Am i right? ). Wont the 2nd method save some time or is it not the best practice for large <TST> files?

OR Does the best practice means writing the code in very few lines which is simple to read & maintain.

First method:

 open (TST, '<c0.ex4.t0.tst');
    abc: while ( $iop = <TST>)
    {
      if( ( $iop =~ /$ra/ ) && ($iop =~ /nop/) )
	      {
		  print "$iop \n";  last abc;
	      }
	
      
    }

second method:

 open (TST, '<c0.ex4.t0.tst');
    abc: while ( $iop = <TST>)
    {
      if( $iop =~ /$ra/ )
	{
	    if ($iop =~ /nop/)
	      {
		  print "$iop \n";  last abc;
               }
	}
      
    }
2

Even in the first method, if the first condition returns false then the second condition is not evaluated due to the logical and operation.

If your requirement is to satisfy two conditions then the first one is a better approach. In case you need to do some other operation after confirming that first condition is satisfied (other than checking second condition) then you may go for the second approach.

3

Thanks for reply. after reading your reply to recall logical AND i searched on internet about it. I have found the following link in support of your reply that 2nd condition gets evaluated only if 1st condition is true in logical AND.
http://publib.boulder.ibm.com/infocenter/comphelp/v8v101/index.jsp?topic=%2Fcom.ibm.xlcpp8a.doc%2Flanguage%2Fref%2Flogande.htm

For my purpose 1st method is best.

Many thanks.