4 ms·
In ES5+, the global `undefined` is immutable, so it should be pretty safe unless someone declared a local `undefined` var in an outer scope.
by kevincennis 11y ago
In ES5+, the global `undefined` is immutable, so it should be pretty safe unless someone declared a local `undefined` var in an outer scope.
- arnehormann 11y agoI use "var undef;" at the top of a function and never set it to a value. Comparison with === is the same as with undefined. And it's nice for minification.