Lab Week 3

Practise Questions No.1

list_data <-  list( c(" Red "," Green "," Black "),list(" Python ", " PHP ", " Java "))
print(" List:")

## [1] " List:"

print(list_data)

## [[1]]
## [1] " Red "   " Green " " Black "
## 
## [[2]]
## [[2]][[1]]
## [1] " Python "
## 
## [[2]][[2]]
## [1] " PHP "
## 
## [[2]][[3]]
## [1] " Java "

print(" Number of objects in the said list:")

## [1] " Number of objects in the said list:"

print(length(list_data))

## [1] 2

print(length(list_data[[1]]))

## [1] 3

print(length(list_data[[2]]))

## [1] 3

Practise Questions No.2

l = list(1,2,3,4,5)
print("Original list:")

## [1] "Original list:"

print(l)

## [[1]]
## [1] 1
## 
## [[2]]
## [1] 2
## 
## [[3]]
## [1] 3
## 
## [[4]]
## [1] 4
## 
## [[5]]
## [1] 5

print("Set 2nd and 3rd elements to NULL")

## [1] "Set 2nd and 3rd elements to NULL"

l[2] <- list(NULL)
l[3] <- list(NULL)
l

## [[1]]
## [1] 1
## 
## [[2]]
## NULL
## 
## [[3]]
## NULL
## 
## [[4]]
## [1] 4
## 
## [[5]]
## [1] 5

Practise Questions No. 3

list1 <- list(g1 = 1:10, g2="R programming", g3="HTML")
print(" Original    list:")

## [1] " Original    list:"

print( list1 )

## $g1
##  [1]  1  2  3  4  5  6  7  8  9 10
## 
## $g2
## [1] "R programming"
## 
## $g3
## [1] "HTML"

print(" New    list:")

## [1] " New    list:"

list1[['g1']] <- list1[['g1']]+10
list1

## $g1
##  [1] 11 12 13 14 15 16 17 18 19 20
## 
## $g2
## [1] "R programming"
## 
## $g3
## [1] "HTML"

Practise Questions No. 4

extract all elements of a first vector except the third element of it from a given list!

new_list1 = list1[['g1']]
new_list1[-3]

## [1] 11 12 14 15 16 17 18 19 20

Practise Questions No. 5

a new item g4 = ”Python” to a given list!

new_item <- list(g4 = "Python")
list1  <- c(list1,new_item)
list1

## $g1
##  [1] 11 12 13 14 15 16 17 18 19 20
## 
## $g2
## [1] "R programming"
## 
## $g3
## [1] "HTML"
## 
## $g4
## [1] "Python"

Practise Questions No. 6

to find all elements of a given list that are not in another given list!

l1 = list ("x","y","z")
l2 = list ("X","Y","Z","x","y","z")
print("Original lists:")

## [1] "Original lists:"

print(l1)

## [[1]]
## [1] "x"
## 
## [[2]]
## [1] "y"
## 
## [[3]]
## [1] "z"

print(l2)

## [[1]]
## [1] "X"
## 
## [[2]]
## [1] "Y"
## 
## [[3]]
## [1] "Z"
## 
## [[4]]
## [1] "x"
## 
## [[5]]
## [1] "y"
## 
## [[6]]
## [1] "z"

print("All elements of l2 that ae not in l1")

## [1] "All elements of l2 that ae not in l1"

setdiff(l2, l1)

## [[1]]
## [1] "X"
## 
## [[2]]
## [1] "Y"
## 
## [[3]]
## [1] "Z"