CODEWITHSUNDEEP
rubynotepad++
amsyar zerø
amsyar zerø

Reputation: 3

How do I fix "in '+': no implicit conversion from Integer to String"?

New user here, so I apologise if this post wasn't formatted correctly.

I am learning how to write Ruby, and I'm using Notepad++. One of the files I'm working on is todemu.rb, which is a file that tells you details about a character called Todemu.

One of the methods I added was:

todemu.age = "27"

to show the age. Then, I put that into a variable so it'd be easier for me to insert that in a sentence.

x = todemu.age
puts "How old is Todemu?"
puts "Todemu is" + " " + x.to_s + " " + "years old."

which displays the output I wanted, Todemu is 27 years old.

Then, I tried to increase the value of the age by using this bit of code:

x += 1

Yet, the console in Notepad++ (I used the NppExec plugin for this) showed this error: todemudan.rb:26:in '+': No implicit conversion of Integer into String (TypeError)

Why does it show the plus sign in the error, and how do I fix this?

Also, I have looked into most of the similarly worded questions in Stack Overflow, but none seem to rectify my problem (thanks iGian for reminding me).

Thanks in advance, and I apologise for the length of the post.

Upvotes: 0

Views: 2673

Answers (2)

Sanjay Prajapati
Sanjay Prajapati

Reputation: 834

You can call .to_i method on the string which represents number. .to_i will coerce the string to integer and .to_f will convert it as float. But make sure string represents number. If you call 'number'.to_i it will return zero

Upvotes: 0

Nick M
Nick M

Reputation: 2532

You keep the age in a String and are trying to apply the “+” operator with an Integer. You should probably store the age as an Integer so you can add to it using “+”. If that is not possible you can always cast using .to_i before adding, eg:

age = x.to_i+1

I’d suggest going through some tutorials that cover Ruby’s type system, for instance: http://zetcode.com/lang/rubytutorial/datatypes/

Ruby's type system forces you to mind your types in such cases rather than for instance PHP's + operator which will concatenate if one of the parameters is a string and the other an integer (without throwing an error)

Integer adding

i = 1
i + 1 # => 2

String + Integer

i = "1"
i + 1 # => error
i.to_i + 1 # => 2
i + "1" # => 11

Interpolation

i = 27
puts "My age is #{i}" # => My age is 27

Upvotes: 4

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