Code
var a
[a] = [2]
console.log("a->",a)
var b = {}
[b] = [3]
console.log("b->",b)
Output
a-> 2
b-> [ 3 ]
Why is the second output different? How is the assignment working?
Thanks
Code
var a
[a] = [2]
console.log("a->",a)
var b = {}
[b] = [3]
console.log("b->",b)
Output
a-> 2
b-> [ 3 ]
Why is the second output different? How is the assignment working?
Thanks
For further actions, you may consider blocking this person and/or reporting abuse
Ogasawara Kakeru -
Arham Rumi -
saifalikhan9 -
zhuyue -
Top comments (5)
You miss semicolon
this would work as expected. It is easy to discover, if you use
let
:Original code:
which is the same as
which is the same as
Thanks a lot. It seemed absurd to me. All makes sense now!
Wow, nice spot, and worrying for me because I never use semicolons anymore. But I also almost never use var. I guess I've been luck so far.
@stereobooster 's explanation about missing semicolon is correct. In JavaScript in order to terminate a block, {}, you need to type a semicolon, ;.
Unexpected behaviour arises in a number of cases like this. I have never seen your case before.
Another example of this is when you return an object literal which spans multiple lines from a function and do not terminate the return statement after the closing brace of the object literal you return. Interpreter can confuse your object literal with a block since they have same syntax.
Telling that I can say that I have seen that case before :).
My suggestion is to use semicolon after at least object literals. You can choose to use semicolons to terminate only blocks and object literals or even after every line to stay safe.
Personally I always use semicolons, I prefer to know exactly where my blocks are terminating. I think it's also that I've been writing JS for so long that I find it unnerving to see no semicolons.