Why ?? 😭😭

Question

https://www.sololearn.com/post/949363/?ref=app

Answer 1

If you want to make it as an assignment operator,

var a = 1
alert(a += 1)

Answer 2

See it like this
a = (+1)
Now does it make sense ?
the + is not addition, it is the sign of the integer 1

Answer 3

Thanks Arsenic Simba for the answer...

Answer 4

Arsenic that means,
a = +1 (a = 1)