Question

One of the things I like the most of JavaScript is that the logical operators are very powerful:

• && can be used to safely extract the value of an object’s field, and will return null if either the object or the field has not been initialized

  // returns null if param, param.object or param.object.field
  // have not been set
  field = param && param.object && param.object.field;
  

• || can be used to set default values:

  // set param to its default value
  param = param || defaultValue;
  

Does PHP allow this use of the logical operators as well?

Answer 1

PHP returns true orfalse. But you can emulate JavaScript’s r = a || b || c with:

$r = $a ?: $b ?: $c;

Regarding ‘ands’, something like:

$r = ($a && $a->foo) ? $a->foo->bar : null;