R: Break for loop

Question

Can you confirm if the next break cancels the inner for loop?

   for (out in 1:n_old){       id_velho <- old_table_df$id[out]       for (in in 1:n)       {        id_novo <- new_table_df$ID[in]        if(id_velho==id_novo)        {         break        }else         if(in == n)        {        sold_df <- rbind(sold_df,old_table_df[out,])        }       }     } 

Answer 1

Well, your code is not reproducible so we will never know for sure, but this is what help('break')says:

break breaks out of a for, while or repeat loop; control is transferred to the first statement outside the inner-most loop.

So yes, break only breaks the current loop. You can also see it in action with e.g.:

for (i in 1:10) {     for (j in 1:10)     {         for (k in 1:10)         {             cat(i," ",j," ",k,"\n")             if (k ==5) break         }        } } 

Answer 2

your break statement should break out of the for (in in 1:n).

Personally I am always wary with break statements and double check it by printing to the console to double check that I am in fact breaking out of the right loop. So before you test add the following statement, which will let you know if you break before it reaches the end. However, I have no idea how you are handling the variable n so I don't know if it would be helpful to you. Make a n some test value where you know before hand if it is supposed to break out or not before reaching n.

for (in in 1:n) {     if (in == n)         #add this statement     {         "sorry but the loop did not break"     }      id_novo <- new_table_df$ID[in]     if(id_velho==id_novo)     {         break     }     else if(in == n)     {         sold_df <- rbind(sold_df,old_table_df[out,])     } }