[SOLVED] IF Statement using OR instead of Else If with AND involved?

[Stryves]

I'm not sure if this is bad practise or not, but is it possible to do this:

 

<?php
if(x=='1' && y=='1' || x=='2' && y=='5')
{
  // Do This
}

 

Instead of

 

<?php
if(x=='1' && y=='1')
{
  // Do This
}
else if(x=='2' && y=='5')
{
  // Do This
}

 

I'd prefer the first method so that I am not duplicating code. I'm noticing that it looks like the code checks "|| x=='2'" and ignore's the &&  so that if x=='2' it runs, and ignores whatever y is equal to.

 

Is that intended?

 

Worst case scenario I'll just use included files to try and avoid reproducing a lot of code.

[Stryves]

I'll try a test run using brackets like:

 

((x=='1' && y=='1') || (x=='2' && y=='5'))

 

and see if this helps... lol.

 

[Ken2k7]

It's not bad practice. In fact, you may need both cases depending on what code you want executed.

 

And you would want to put parentheses there.

[Zhadus]

You need to use the parenthesis, but it will be fine then.

 

This code:

if(x=='1' && y=='1' || x=='2' && y=='5')

 

is equivalent to:

if(((x=='1') && (y=='1') && (y=='5')) || (x=='2'))

[premiso]

((x=='1' && y=='1') || (x=='2' && y=='5'))

 

That is how it should be done if that is what you want. Way to solve your own question

[GingerRobot]

Stryves: Assuming the "Do This" code is the same, they're logically equivalent. However, the first is obviously nicer as it means you don't have to repeat that code.

 

The if statement your first presented is indeed valid - the && operator has a higher precedence than the || operator, so is evaluated first. See this manual page for more on precedence. All that said, i personally would prefer to add the extra brackets as it makes it easier to read and you or other people are less likely to mistake the purpose of the if statement. E.g.:

 

if( ($x=='1' && $y=='1') || ($x=='2' && $y=='5') )

[Stryves]

I knew this was the right place to come... Just seconds after posted and trying to ensure I didn't sound like an idiot it clicked... "Oh right, brackets!"

 

Thanks everyone!

 

[GingerRobot]

Like I said though, in the above case the brackets aren't actually necessary - I would still use them, however.