Problem 6. Select every other element of a vector

Created by Cody Team
Appears in 3 groups

Difficulty:Rate

Solve Later
Add To GroupÃ‚

Write a function which returns every other element of the vector passed in. That is, it returns the all odd-numbered elements, starting with the first.
Examples:
 Input  x = [1 3 2 4 3 5]
 Output y is [1 2 3]
 Input  x = [5 9 3 2 2 0 -1]
 Output y is [5 3 2 -1]

Solve

Solution Stats

81843 Solutions
34601 Solvers

Last Solution submitted on Jun 13, 2025

Last 200 Solutions

Problem Comments

41 Comments

41 Comments

Show 38 older comments

Oleg Komarov on 26 Jan 2012

Not clear.

Giuseppe Cardillo on 1 Feb 2012

What does it mean? It is not clear

Hristo Alexiev on 1 Feb 2012

It's not understandable.

Aurelien Queffurust on 3 Feb 2012

This problem is definitely not clear.

Martin on 7 Feb 2012

Select the first, the third, the fifth, the seventh, ... element.

Sumit Agrawal on 30 Mar 2013

nice problem

kurguz on 6 Apr 2013

I cant understand this problem.

Maciej Kusper on 4 Jun 2013

nice

Jon on 13 Nov 2013

All solutions with score 10 or 11 use the regexp cheat.

L.K.R.Chaithanya kumar on 15 Jul 2014

very good one

Armando Femat on 3 Dec 2015

Yes, you should change the redaction of the problem,maybe

Mir Rejaul Karim on 16 Jul 2016

function y = everyOther(x)
for i=1:length(x)
if mod(x(i),2)~=0
y(i)=x(i)
end
end
y=y(y>0)

end

What's wrong with this solution?

Rong Zeng on 21 Aug 2016

y = x(mod(x,2)==1);
it's not working, and i cant see why

Vineet Kumar on 25 Aug 2016

nice problem

SIVAPRAKASH DANABALASINGAM on 10 Jan 2017

nice

Taha MRIHEEL on 3 Apr 2017

good

N/A on 6 Apr 2017

I can't understand, why is this wrong?
j=1;
for i=1:length(x)
if rem(x(i),2)~=0
y(j)=x(i);
j=j+1;
end
end

Barrie Cooper on 25 Apr 2017

Nice problem, but I have been doing this with my son and it would be good if the exercises were more gently graduated with relevant syntax so he can learn without relying on his dad knowing Matlab!

James Tanner on 26 Jun 2017

I can't believe someone solved this with size 9.

Gulen Insay on 2 Sep 2017

The leading solution is not a solution. It just makes all the test assertions true.

Ghetto blaster on 22 Oct 2018

Indexing is one of more important things in matlab and matrices. Gotta learn them good before heading on.

Banana on 25 Sep 2019

Helo, hey hey ey

Matlab Expert on 7 Mar 2020

Indexing is one of more important things in matlab and matrices. Gotta learn them good before heading on.

Simone Tiero on 1 Nov 2020

Test suite suggests solution !

Teo Lungoci on 7 Feb 2021

nice

Muhtasim Haque Nahian on 21 Apr 2021

the example made confusion

chan chan on 3 May 2021

cool!

Nathan Hon on 14 Oct 2021

nice!

建国田 on 26 Oct 2021

cool!

Zachary Hill on 13 Dec 2021

hard

Erin Paisner on 18 Dec 2021

I overcomplicated this one at first, but once you figure it out, it's not too bad

Christian on 20 Nov 2022

Absolutely mind boggling

Robert on 11 Dec 2022

this one's pretty good

David on 14 Jul 2023

gg ez

shaocong linghu on 28 Aug 2023

I have a question is that :test6 and test7 is the column vector,but test1-5 is the row vector,
so if test 1-5 are passed ,the test 6 and 7 are not passed

YiFei Wang on 30 Nov 2023

这个问题出的有点问题，没有规范化

anuraag on 5 Mar 2024

gg ez

HK on 27 Apr 2024

OMG, It wasn't about finding the odd numbers?

Muhammad on 26 Aug 2024

Below is my code but it is failing the test 6 and 7. I tried inputting x=randi(100,10,1) and x=primes(20) in the scratchpad and the code works fine, outputing the right answer. There seems to be a problem with the evaluation of the answers.

function y = everyOther(x)
y = [];
for i = 1:2:length(x);
y(end+1) = x(i);
end

Dyuman Joshi on 29 Aug 2024

@Muhammad, take a deeper look at what the test cases are testing for.

Ivo on 27 Mar 2025

y = x(1:2:end);

does the trick. :)

Solution Comments

Show comments

Problem Recent Solvers34601

Problem Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Problem 6. Select every other element of a vector

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers34601

Suggested Problems

More from this Author96

Problem Tags

Community Treasure Hunt

Problem 6. Select every other element of a vector

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers34601

Suggested Problems

More from this Author96

Problem Tags

Community Treasure Hunt

Players