小编Mec*_*eit的帖子

你可以这样复制:

var test = {'var1': 'bacon'};

"var1" in test;             // Returns true  - Correct
!"var1" in test;            // Returns false - Correct
"nonexistant" in test;      // Returns false - Correct
!"nonexistant" in test;     // Returns false - Incorrect - This should be true.. should it not?