PHP Short Code

1. ternary vs coalescing null operator
1. checks for null values
2. example:
   echo isset($item_name) ? $item_name : NULL;
   echo $item_name ?? NULL;
   
2. ternary vs elvis operator (ternary shorthand)
1. checks for truthy values
2. example:
   echo !empty($item_name) ? $item_name : NULL;
   echo $item_name ?: NULL;
   
3. using ternary vs (coalescing null operator & elvis operator)
1. example:
   echo isset($item_name) && !empty($item_name) ? $item_name : ‘default’;
   echo $item_name ?? $item_name ?: ‘default’;
   
4. spaceship operator
1. used to compare 2 values and returns either -1,0,1. mostly used to compare dates
2. example:
   var_dump(1 <=> 2); // returns int(-1)
   var_dump(1 <=> 1); // returns int(0)
   var_dump(2 <=> 1); // returns int(1)