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Cover image for Guess the output of this JS code
Shuvo
Shuvo

Posted on

Guess the output of this JS code

Try to guess the output of this code without running it. Let me know in the comment what you got πŸ˜‰

let num = 10;
for(let i = 0; i < num; i++){
    console.log(num);
    num--;
}
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hint: You may have got the first half right

Top comments (16)

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fjones profile image
FJones

Output (i/num after iteration):
10 (1/9)
9 (2/8)
8 (3/7)
7 (4/6)
6 (5/5) - loop terminates as !(i < num).

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lukeshiru profile image
Luke Shiru

The output of this code is me telling you to fix that code 🀣 ... jokes aside, if you see a pice of code like this, your first question should be:

What were you trying to do?

I'm sure that if you see this in "production", there was a typo somewhere, because the actual behavior (looping down from 10 to 6), can be achieved with a much clearer code, so is surely a mistake if you see something like that.

Cheers!

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0shuvo0 profile image
Shuvo Author

Yes, It was just a trick question for newbies

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lukeshiru profile image
Luke Shiru

I know, and my comment is explaining "newbies" that you don't always have to resolve the problem in interviews. Sometimes the best answer is: "I don't understand your code/intention", instead of banging your head against the keyboard.

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abdelrahman_dwedar profile image
β€˜AbdelraαΈ₯man Dwedar πŸ‘¨πŸ»β€πŸ’»πŸ‡΅πŸ‡Έ

Nice one!

The solution is:
10
9
8
7
6

The explanation:
1- It'll output 10 since we didn't change it yet.
2- We'll increase i to 1 and num decreased to 9.
3- Increases i to 2 and num decreased to 8.
4- Increases i to 3 and num decreased to 7.
5- Increases i to 4 and num decreased to 6.
Then it ends, 'cause num will be 5 while i will be the equal, so it stops.

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rexion21 profile image
Gerardo Leonel Blesly

10
9
8
7
6
5
4
3
2
am i correct?

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0shuvo0 profile image
Shuvo Author

Thanks for trying. but actually its wrong

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janpauldahlke profile image
jan paul

a unicorn bookmark well earned. ty for this.

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0shuvo0 profile image
Shuvo Author

Many many Thank s πŸ’“

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gamer1478 profile image
Aayush Garg

10
9
8
7
6
this should be the output.

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path08 profile image
PATH

Is it uhmm

10
9
8
7
6

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0shuvo0 profile image
Shuvo Author

Correct

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deeyestea profile image
deeyestea

10, 9, 8, 7, 6

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0shuvo0 profile image
Shuvo Author

Correct

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thiennguyen1tiki profile image
thien-nguyen1

10, 9, 8, 7, 6
for loop stop when num = 5, ( every console.log in for decrease num for 1 )

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0shuvo0 profile image
Shuvo Author

right

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