my text file :
jack,28,25.2 smith,23,10.5 lena,49,11 leo,29,21.9 sara,38,44 ibra,23,11.5 Ayan,29,45
sample <- read.table("sample.txt", sep = "|", header=F) colnames(sample) <- c("name","age","income")
i try to change name of col but i have error:
'names' attribute  must be the same length as the vector 
Welcome to Stackoverflow, Abdullah Alotaibi!
As mentioned in the comments you should use
read.csv("sample.txt", header=FALSE) or
read.csv("sample.txt",sep=",", header=FALSE) .
Because of the use of
, as seperator in your textfile.