Exc

employee_names <- c("Belinda Johnes","Maria Delar", "Math Smith", "Matt Williams", "Robert Mathews",
  "Julia Walters", "Andrea Cheng", "July Horitz", "Danielle Muller", "Esteban Lugo")
typeof(employee_names)

## [1] "character"

salary <- c(3000, NA, NA, NA, NA, 4000, 3000, 5000, 1000, 5000)
typeof(salary)

## [1] "double"

names(salary)<-employee_names
salary

##  Belinda Johnes     Maria Delar      Math Smith   Matt Williams  Robert Mathews 
##            3000              NA              NA              NA              NA 
##   Julia Walters    Andrea Cheng     July Horitz Danielle Muller    Esteban Lugo 
##            4000            3000            5000            1000            5000

#attributes(salary)
#names(salary)
#salary
names(salary)<-NULL
salary

##  [1] 3000   NA   NA   NA   NA 4000 3000 5000 1000 5000

salary[6]

## [1] 4000

salary[-2]

## [1] 3000   NA   NA   NA 4000 3000 5000 1000 5000

salary[c(1,3,5,7,9)]

## [1] 3000   NA   NA 3000 1000

#alternatively
salary[seq(1,9,2)]

## [1] 3000   NA   NA 3000 1000

salary[-(4:6)]

## [1] 3000   NA   NA 3000 5000 1000 5000

salary[salary>3000]

## [1]   NA   NA   NA   NA 4000 5000 5000

s<-seq(2,30,2)
s

##  [1]  2  4  6  8 10 12 14 16 18 20 22 24 26 28 30

attributes(s)

## NULL

dim(s)<-c(3,5)
s

##      [,1] [,2] [,3] [,4] [,5]
## [1,]    2    8   14   20   26
## [2,]    4   10   16   22   28
## [3,]    6   12   18   24   30