title: Null coalescing operator also usable with falsy values, but not nulls?
body: <p>The new <strong>null coalescing operator</strong> in PHP is surely a great feature, somewhat comparable to JavaScript's usage of <code>||</code> for getting default values.</p>
  
  <p>I already read some documentations and articles about this feature, but some things are still not quite clear to me.</p>
  
  <p><strong>1.</strong> Can I use this operator with any number of operands? For example, would this be valid?</p>
  
  <p><code>$a = $p1 ?? $p2;</code></p>
  
  <p><code>$b = $r1 ?? $r2 ?? $r3 ?? $r4 ?? $r5;</code></p>
  
  <p><strong>2.</strong> What is about falsy values, which are not null?</p>
  
  <p><code>$test = false ?? 0 ?? 'test';</code> - what will be <code>$test</code> now? If it doesn't work with falsy values other than null, how can we achieve, that it works like JavaScript's <code>||</code>?</p>