How to print concatenated string a result of each for loop iteration in R

Question

This code words as intended in Python:

my_books = ['R','Python','SQL','Java','C']

cou = 0
for i in my_books:
    cou = cou + 1
    print('Book Number:',cou,'&','Name of the book:',i)
print('\nNo more books in the shelf')

Output is:

Book Number: 1 & Name of the book: R
Book Number: 2 & Name of the book: Python
Book Number: 3 & Name of the book: SQL
Book Number: 4 & Name of the book: Java
Book Number: 5 & Name of the book: C

No more books in the shelf

Whereas in R, how to get the same output? My code in R as below:

my_books = c('R','Python','SQL','Java','C')

cou = 0
for(i in my_books){
  cou = cou + 1
  paste('Book Number:',cou,'&','Name of the book:',i)
}
print('No more books in the shelf')

The output I get is: [1] "No more books in the shelf"

Is there a different function to use within a for loop?

Is there a reason why we need to use paste inside a print function in a loop? In this code it works fine as a standalone: weather_report <- function(Cel = as.numeric(readline('Enter the temperature in C:'))){ F = Cel*1.8 + 32 if(F > 90){ ans <- 'It\'s too hot' print(ans) } else{ ans <- 'It\'s not too hot' print(ans) } paste('Temperature in F =',F) } — Karthik S
– Karthik S, Commented Feb 2, 2019 at 4:26
If you need to concatenate different objects together you need to use paste and since it does not automatically print in for loop, you need to explicitly mention that as well. In the function above there is no for loop, hence paste works fine. — Ronak Shah
– Ronak Shah, Commented Feb 2, 2019 at 4:32

Ronak Shah · Accepted Answer · 2019-02-02 04:27:16Z

You just need to print the paste part as it is in the loop. In loop you have to explicitly tell to print the things.

my_books = c('R','Python','SQL','Java','C')

cou = 0
for(i in my_books){
  cou = cou + 1
  print(paste('Book Number:',cou,'&','Name of the book:',i))
}


#[1] "Book Number: 1 & Name of the book: R"
#[1] "Book Number: 2 & Name of the book: Python"
#[1] "Book Number: 3 & Name of the book: SQL"
#[1] "Book Number: 4 & Name of the book: Java"
#[1] "Book Number: 5 & Name of the book: C"

However, let me show you the magic of R. You can avoid the loop by doing

paste('Book Number:', seq_along(my_books), '& Name of the book:', my_books)

#[1] "Book Number: 1 & Name of the book: R"     
#[2] "Book Number: 2 & Name of the book: Python"
#[3] "Book Number: 3 & Name of the book: SQL"   
#[4] "Book Number: 4 & Name of the book: Java"  
#[5] "Book Number: 5 & Name of the book: C"

Collectives™ on Stack Overflow

How to print concatenated string a result of each for loop iteration in R

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related