shreyas-a/js-gotchas

JavaScript Gotchas and Common Mistakes

js-gotchas

JavaScript Gotchas and Common Mistakes

1. 0 is falsy but "0" is true.

   if (0) {
       console.log('yey.');
     } else {
       console.log('boom'); // this will be printed
     }
   
   
   if ("0") {
       console.log('yey.'); // this will be printed
     } else {
       console.log('boom'); 
     }

2. NaN is not a NaN.

   NaN === NaN   // false

   During the evaluation of a tripple equals a === b following things are considered. FYI typeof NaN is number

   • If typeof a is different from typeof b, return false.
   • If typeof a is number, then
     • If a is NaN, return false.
     • If b is NaN, return false.