Concatenating sting with number

Question

The code below in javascript
var x="20"; alert(x*1+20);

Can someone explaine how this output= 40 ?

Answer 1

Because that time, only addition is perform with variable x,
and it is treated as string that time. So that x and 20 can concat. 😅

JavaScript is very moody language.

Answer 2

Simply,
JavaScript is a multi talented language 😁
It automatically converts a datatype when needed.
In your code,
you performed some calculations, so x variable is treated as int, so calculated as-
20*1+20 which is 40

Answer 3

20 * 1 = 20
20 + 20 = 40

Answer 4

but why when alert(x+20);
the result is 2020?