I was given a short javascript code in an interview to give the output of that but I was not sure what will be the output of that. He creates a var object and assigns objects as indexes of that object using the array data structure. I did console that code after the interview but still do not understand how it is showing the output.
Here is the code
var a = {};
b = { key: 'b'};
c = { key: 'c'};
a[b] = 123;
a[c] = 456;
console.log(a[b]); //what is the output of this console statement and explain whyCan anyone explain with javascript logic behind the output it shows? Thanks in advance!
The object used as key's toString is [object Object] and that is what is used each time
var a = {};
b = { key: 'b'};
c = { key: 'c'};
a[b] = 123; // sets a["[object Object]"]
console.log(b,a[b])
a[c] = 456; // ALSO sets a["[object Object]"]
console.log(b,a[b])
console.log(Object.keys(a))
console.log(a[b]);
console.log(a["[object Object]"]);You could have a look to the object a, where you see the stringed object (with toString())
[object Object]
as accessor.
Objects can have only strings as properties and with the latest Symbol, it could be this one, too.
var a = {};
b = { key: 'b'};
c = { key: 'c'};
a[b] = 123;
a[c] = 456;
console.log(a[b]); //what is the output of this console statement and explain why
console.log(a);