Why does `{foo: 1}` evaluate to `1` in the console, and `{foo: 1, bar: 2}` results in an error?

Question

I knew that {} is either an object or a block of code, but today my co-worker asked me why {foo: 1} works when entered into the console, but

Answer 1

i'm sorry not to comment under your post due to lack of reputation.

can you elaborate more on "Why I can print foo: 1 in JavaScript"?

If I run this code

var t = {foo: 1};

It will become the property for object "t". The same behaviour will be implement if you use this code

var t = {foo: 1, bar: 2};

You can access it by "t.foo" and "t.bar" and it will return the value either "1" or "2".

You can read the explanation of "object" here JavaScript Objects