Replace NA values with value from another column in same dataframe [duplicate]

Question

I would like to replace NA in a particular column with values from another column in same dataframe

DF1:

Item    From    Price    Discount    NewPrice
 A     Delhi    100        .10         110
 A     Mumbai   200        .10         120
 A     Pune     150         NA          NA
 A     Nagpur   200        .10          NA

I would like to replace NA in NewPrice with the values in column Price

I have referred this but it is not helping Replace empty values with value from other column in a dataframe

Have tried below one but not working

df$NewPrice <- ifelse(df$NewPrice == "", df$Price, df$NewPrice)

Answer 1

I would try with standard subsetting:

#subset the NAs of new price with the ones from price
df$NewPrice[is.na(df$NewPrice)] <- df$Price[is.na(df$NewPrice)]

Out:

df
#  Item   From Price Discount NewPrice
#1    A  Delhi   100      0.1      110
#2    A Mumbai   200      0.1      120
#3    A   Pune   150       NA      150
#4    A Nagpur   200      0.1      200