The feature isn't bad, but there are several warts. The '$' is not a prefix operator on strings. The following is a syntax error: $"test"; It turns out th

The feature isn't bad, but there are several warts. The '$' is not a prefix operator on strings. The following is a syntax error: $"test"; It turns out that '$' can only operate on an identifier or another '$' expression. The '${...}' syntax, aside from being more readable and less likely to be accidentally encountered, is more like an operator: ${"test"}; // equivalent to $test The decision to keep (and only warn against) unescaped strings past the introduction of an incompatible feature (constants) is inexcusable. It creates oddities: $test = 'foo'; $foo = 42; echo $test . " ${test} " . ${test} . " " . $$test . "\n"; This generates a notice and prints, "foo foo foo 42". But then: $test = 'foo'; $foo = 42; define('test', 'foo'); echo $test . " ${test} " . ${test} . " " . $$test . "\n"; This will print, "foo foo 42 42". (Note also the difference between the meaning of ${...} within string interpolation versus outside of it.) Is this all understandable? Sure. Is it good? No.