# Stupid TypeError while checking array values

**URL:** <https://www.ruby-forum.com/t/stupid-typeerror-while-checking-array-values/71556>\
**Category:** Ruby\
**Created:** [October 9, 2006, 10:17pm UTC](https://www.ruby-forum.com/t/stupid-typeerror-while-checking-array-values/71556 "2006-10-09T22:17:24Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![kly](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/34f0e0/32.png) [@kly](https://www.ruby-forum.com/u/kly)\
**Post date:** [October 9, 2006, 10:17pm UTC](https://www.ruby-forum.com/t/stupid-typeerror-while-checking-array-values/71556/1 "2006-10-09T22:17:24Z")

</div>

Not sure if I’m even close to the mark on this. Ruby noob here…RACKIN  
M’BRAINS HERE!! ☹

I am trying to check values of an array against another value.  
Unfortunately, I keep getting a TypeError that says:

can’t convert User into Integer

I am trying to check if a logged in user has access to a course id based  
on ownership assignments.

I have 2 tables having M:M relationship and a join table:

* * *

- 

```
         *

```

- Courses \*
- 

```
         *

```

* * *

* * *

- 

```
               *

```

- Courses\_Users \*
- 

```
               *

```

* * *

* * *

- 

```
         *

```

- Users \*
- 

```
         *

```

* * *

…and here is my action

def user\_assigned\_course(course\_id, user\_id)  
allowed\_users = Course.find\_by\_id(course\_id).users  
allowed\_users.each do |user|  
if allowed\_users[user] == user\_id  
return true  
end  
end  
end

…help…

---

<div class="post-metadata">

**Author:** ![kly](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/34f0e0/32.png) [@kly](https://www.ruby-forum.com/u/kly)\
**Post date:** [October 9, 2006, 10:19pm UTC](https://www.ruby-forum.com/t/stupid-typeerror-while-checking-array-values/71556/2 "2006-10-09T22:19:59Z")

</div>

Ooops: forgot to add “.id” after “allowed\_users[user]”

> …and here is my action
> 
> def user\_assigned\_course(course\_id, user\_id)  
> allowed\_users = Course.find\_by\_id(course\_id).users  
> allowed\_users.each do |user|  
> if allowed\_users[user] == user\_id  
> return true  
> end  
> end  
> end
> 
> …help…

def user\_assigned\_course(course\_id, user\_id)  
allowed\_users = Course.find\_by\_id(course\_id).users  
allowed\_users.each do |user|  
if allowed\_users[user].id == user\_id  
return true  
end  
end  
end

---

<div class="post-metadata">

**Author:** ![kly](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/34f0e0/32.png) [@kly](https://www.ruby-forum.com/u/kly)\
**Post date:** [October 9, 2006, 10:20pm UTC](https://www.ruby-forum.com/t/stupid-typeerror-while-checking-array-values/71556/3 "2006-10-09T22:20:38Z")

</div>

…yet this didn’t fix the error, so still:

HELP! 😕

---

<div class="post-metadata">

**Author:** ![kly](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/34f0e0/32.png) [@kly](https://www.ruby-forum.com/u/kly)\
**Post date:** [October 9, 2006, 10:42pm UTC](https://www.ruby-forum.com/t/stupid-typeerror-while-checking-array-values/71556/4 "2006-10-09T22:42:53Z")

</div>

1 def user\_assigned\_course(course\_id, user\_id)  
2 allowed\_users = Course.find\_by\_id(course\_id).users  
3 allowed\_users.each do |user|  
4 if allowed\_users[user].id == user\_id  
5 return true  
6 end  
7 end  
8 end

change line 4 to:  
if user.id == user\_id  
user is not an index, it is an actual value.

BTW: you could also:

1. write return true before if (replace lines 4-5 with):

return true if user.id == user\_id

1. use array function any? (replace lines 3-7 with):

return true if allowed\_users.any? {|user| user.id == user\_id }

probably you can even omit the ‘return true if’ part, so the whole  
func could collapse to

def user\_assigned\_course(course\_id, user\_id)  
Course.find\_by\_id(course\_id).users.any? {|user| user.id == user\_id }  
end

although this might be too tight, as the left out ‘allowed\_users’ adds  
meaning to the .users array.

---

<div class="post-metadata">

**Author:** ![kly](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/34f0e0/32.png) [@kly](https://www.ruby-forum.com/u/kly)\
**Post date:** [October 9, 2006, 10:30pm UTC](https://www.ruby-forum.com/t/stupid-typeerror-while-checking-array-values/71556/5 "2006-10-09T22:30:10Z")

</div>

Rick A. wrote:

> Ooops: forgot to add “.id” after “allowed\_users[user]”
> 
> > …and here is my action
> > 
> > def user\_assigned\_course(course\_id, user\_id)  
> > allowed\_users = Course.find\_by\_id(course\_id).users  
> > allowed\_users.each do |user|  
> > if allowed\_users[user] == user\_id  
> > return true  
> > end  
> > end  
> > end
> > 
> > …help…
> 
> def user\_assigned\_course(course\_id, user\_id)  
> allowed\_users = Course.find\_by\_id(course\_id).users  
> allowed\_users.each do |user|  
> if allowed\_users[user].id == user\_id  
> return true  
> end  
> end  
> end

_ooops_ _blush_

this worked:

def user\_assigned\_course(course\_id, user\_id)  
allowed\_users = Course.find\_by\_id(course\_id).users  
for user in allowed\_users  
if user.id == user\_id  
return true  
end  
end  
end

---

<div class="post-metadata">

**Author:** ![kly](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/34f0e0/32.png) [@kly](https://www.ruby-forum.com/u/kly)\
**Post date:** [October 9, 2006, 10:58pm UTC](https://www.ruby-forum.com/t/stupid-typeerror-while-checking-array-values/71556/6 "2006-10-09T22:58:56Z")

</div>

Rick A. wrote:

> def user\_assigned\_course(course\_id, user\_id)  
> allowed\_users = Course.find\_by\_id(course\_id).users  
> for user in allowed\_users  
> if user.id == user\_id  
> return true  
> end  
> end  
> end

And if you want to make your code a little bit cleaner, you can take  
advantage of Ruby’s Enumerable#any? method:

def user\_assigned\_course(course\_id, user\_id)  
Course.find\_by\_id(course\_id).users.any? { |u| u.id == user\_id }  
end

Jamey

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---

<div class="post-metadata">

**Author:** ![kly](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/34f0e0/32.png) [@kly](https://www.ruby-forum.com/u/kly)\
**Post date:** [October 9, 2006, 11:26pm UTC](https://www.ruby-forum.com/t/stupid-typeerror-while-checking-array-values/71556/7 "2006-10-09T23:26:59Z")

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On 10/9/06, Rick A. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> Wow, thanks guys! I better read up on making my Ruby code more  
> efficient…

You’re welcome. It really helps to browse the docs (e.g.  
ruby-doc.orc/core) to see what’s in. Especially the Array, Hash,  
String, Enumerable contain a lot of shortcuts.

J.

---

<div class="post-metadata">

**Author:** ![kly](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/34f0e0/32.png) [@kly](https://www.ruby-forum.com/u/kly)\
**Post date:** [October 9, 2006, 11:19pm UTC](https://www.ruby-forum.com/t/stupid-typeerror-while-checking-array-values/71556/8 "2006-10-09T23:19:26Z")

</div>

Wow, thanks guys! I better read up on making my Ruby code more  
efficient…

Rick