javascript - confusion with instanceof Array and String -

this question has answer here:

• why instanceof return false literals? 10 answers

i read instanceof answer,but have question when code

["a","b"] instanceof array 

why reutrns true same

new array("a","b") instanceof array 

while

"a" instanceof string 

returns false not same

new string("ab") instanceof string  

? appreciate answers , help!

for strings, have both

• primitive strings (the ones manipulate of times, , literals)
• and instances of string class.

and they're not same.

here's what mdn says on distinction between both.

another way see difference, mdn doesn't point, can add properties on objects :

var = "a"; a.b = 3; // doesn't add property wrapped copy console.log(a.b);  // logs undefined = new string("a"); a.b = 3; console.log(a.b);  // logs 3 

(remember of times, should use primitive strings)

for arrays, have arrays, there nothing primitive array.