what it will print console.log(1+ + “2”)

Question

Why does this JavaScript statement:

console.log(1 +  + \"2\");

print

3

as the output? I am not sure why

Answer 1

console.log(1 + "2") prints 12 as + acts as an concatenation operator.

But if you try to print console.log( + "2" ) you will get output as 2 coz it is casted as an integer.

Therefore console.log( 1 + +"2" ) will give you result as 3

Answer 2

Regarding the specific output of

console.log(1 +  + "2");

Run it on your browser console. The better question is why does it output what it does -

console.log(1 +  + "2");
              ^

That is the binary + operator, which will concatenate strings or add numbers.

console.log(1 +  + "2");
                 ^

That one is the unary + operator, which converts "2" to a number.

Don't create JavaScript like this. It's confusing.

Answer 3

+ or - operand in front of a string converts it to number. so here +"2" will become 2 hence the result will be 3.

=> 1 + + "2"    // +"2" = 2
=> 1 +    2
=> 3

If you use - in between like

=> 1 - - "2"   // -"2" = -2
=> 1 - - 2     // 1 - (-2)
=> 1 + 2
=> 3

So,

     -"2" ==> -2
     +"2" ==>  2
 +"Hello" ==> NaN
 -"Hello" ==> NaN