Having syntax errors with if statements - r

Question

I have the following question:
In the imported data frame, I need to create a new column named “profit_margin_flag” whose value is computed as follows [profit margin = Profit / Sales].
a.If the profit margin is negative, the new column should have the value “negative”.
b.If the profit margin is positive and less than 10%, the new column should have the value “low margin”.
c.If the profit margin is 10% or more, but less than 25%, the new column should have the value “standard margin”.
d.If the profit margin is 50% or more, the new column should have the value “high margin”.
I coded this:
orders$profit_margin_flag <- orders$Profit/orders$Sales
n <- nrow(orders)
`for (i in (1:n))`
{
if(orders$profit_margin_flag[i] < 0)
{orders$profit_margin_flag[i] <- "negative"}
else if(orders$profit_margin_flag[i] >0 && <.10)
{orders$profit_margin_flag[i]<- "low margin"}
else if(orders$profit_margin_flag[i] >= .10 && < .25)
{orders$profit_margin_flag[i]<- "standard margin"}
else if(orders$profit_margin_flag[i] >= .50)
{orders$profit_margin_flag[i]<- "high margin"}
}
I receive this error:
else if(orders$profit_margin_flag[i] >0 && <.10)
#Error: unexpected 'else' in " else"
# {
+ orders$profit_margin_flag[i]<- "low margin"
+ }
else if(orders$profit_margin_flag[i] >= .10 && < .25)
Error: unexpected 'else' in "else"
{orders$profit_margin_flag[i]<- "standard margin"}
else if(orders$profit_margin_flag[i] >= .50)
Error: unexpected 'else' in " else"
{orders$profit_margin_flag[i]<- "high margin"}
}
Error: unexpected '}' in "}"

Answer 1

As #mickey pointed out, && < .10 isn't valid syntax.
That being said, do you want to replace profit_margin_flag's value with "negative" etc. (as you specific in the OP) or do you want it assigned to a new variable?
I cleaned up your code a little bit (with the flag being assigned to a new variable profit_margin_flag and the margin values originally being stored in profit_margin) and this should work.
orders <- data.frame(profit_margin = c(-2, 0.07, 0.14, 11), profit_margin_flag = rep_len(NA, 4))
for(i in 1:nrow(orders)){
+ if(orders$profit_margin[i] < 0){
+ orders$profit_margin_flag[i] <- "negative"
+ }
+ else if(orders$profit_margin[i] > 0 && orders$profit_margin[i] < 0.10){
+ orders$profit_margin_flag[i]<- "low margin"
+ }
+ else if(orders$profit_margin[i] >= 0.10 && orders$profit_margin[i] < 0.25)
+ {
+ orders$profit_margin_flag[i]<- "standard margin"
+ }
+ else if(orders$profit_margin[i] >= 0.50)
+ {
+ orders$profit_margin_flag[i]<- "high margin"
+ }
+ }
orders
# profit_margin profit_margin_flag
# 1 -2.00 negative
# 2 0.07 low margin
# 3 0.14 standard margin
# 4 11.00 high margin