At the risk of beating a dead horse:

The ternary expression is an expression, whereas the if equivalent is a statement.

In even more other words, the if statement cannot be used as a component of an expression while the ternary operator can.

So, this:

my $x = $is_true ? 'is true!' : 'is false';

may be considered a shorter way of saying this (note that the my $x; must appear outside of the if):

my $x;
if ($is_true) {
  $x = 'is true!';
}
else {
  $x = 'is false!';
}
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But, one cannot always simply condense an arbitrary if statement into a ternary expression

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