[Split a variable if it has a delimiter]

I am trying to split a variable only if it has an integer. Here is what I want to do:

 

$id = 1234-54678;

 

should be split into and then placed into two variables:

 

$id1 = 54678;

$id2 = 1234;

 

Sometimes the variable may not have a delimiter in which case I would like it to be $id1

 

example:

$id = 54678;

 

should go directly to

 

$id1 = 54678;

 

I am a php rookie and don't know which way is best to do this (explode, split, etc.) so I would appreciate any help you can give me.