Explain the output of this code !!!!!

Question

var num1 = [1,2] ;
var num2 = [3,4] ;
var set = num1 + num2 ;
console.log(set.length);

Output : 6

Why output is 6 ?? How it works ???

Answer 1

This happen because "+" sign works for numbers and strings. And here "+" automatically convert array to string: "1,2"+"3,4" = "1,23,4". So "1,23,4" as string has length 6.

Answer 2

What is the output of the following code?
let nums = [3, 4, 5];
let all = [1, 2, ...nums, 6];
console.log(all[3]);

answer

4

Answer 3

hangout..? i dont use it....

Answer 4

I am also done.

Answer 5

Parisa Baastani Console.log output any statement in java script. Document.write display it in html document but console.log displays it directly in console.

Answer 6

Vladi Petrov Thank you so much !!!!

Answer 7

im done.....

Answer 8

Vladi Petrov Thank you so much. I would like to ask a question. Would you like to join our programming group ???

Answer 9

Ok

Answer 10

i dont know about cinsole.log, anybody here to explain about it?

Answer 11

Hi,
'var' datatype behaves as what type of data is initialized that's why initialization is necessary while declaring 'var' variable.

'+' sign is considered as concatenate operator when used with string values.

Since right side is string then 'var' will behave like a string.

Length function returns the length of a string that's why answer is 6.
Thanks,
Jai Patel

Answer 12

What is the output of this code?
function letItBe() {
let v = 2;
if (true) {
let v = 4;
console.log(v);
}
console.log(v);
}
letItBe();

Ans: 4 2

Answer 13

S. Kaouche Nope It isn't because of .length method

Answer 14

[3] means, the fourth ---> 4

Answer 15

ya that what i was thinking...

Answer 16

if you are counting "commas(,)", then also length will be 5. Why are you taking 23 separately? they are single as number twenty three(according to what output you showed)

Answer 17

ya.. shit now i got that.. i just forgot nd got confused.. sorry Vladi

Answer 18

Isn't it because of the .length method which add 0 position to each array ?
So it becomes 0,1,2 (num1)+ 0,3,4 (num2)= 6
The 0 position index is included in the .length method , isn't it ?

Answer 19

you can add two arrays in JS using the concat method. var v = a.concat(arr); console.log(v)

Answer 20

What is the output of the following code?
let nums = [3, 4, 5];
let all = [1, 2, ...nums, 6];
console.log(all[3]);

answer

4