Dataset

exam_score1 = data.frame(
ID = c(1, 2, 3, 4, 5),
Names = c("Alice","Bob","Devi", "John", "Bibi"),
Age = c(20, 25, 30, 22, 23),
Score = c(10, 20, 30, 40, 50)
)
print(exam_score1)

#vector[location]
#data[row, colm]
exam_score1[2:4, ]

exam_score1[ ,3:4]

exam_score1[2:4,3:4]

#if we want to select specific row or column
#by forming dataset

exam_score1$Names

[1] "Alice" "Bob"   "Devi"  "John"  "Bibi" 

exam_score1$Age

[1] 20 25 30 22 23

selected_segment = data.frame(
  name = exam_score1$Names,
  age = exam_score1$Age
)
print(selected_segment)

#another way if we want to select specific row or column
#vector can be used
exam_score1[c(2, 3, 4), c(3, 4)]

#condition selection in dataset
exam_score1[exam_score1$Score >30, ]

#condition selection in dataset
exam_score1[exam_score1$Score > 30 & exam_score1$Score < 50, ]

selected_id = c(1, 3, 4)
exam_score1[exam_score1$ID %in% selected_id, ]

#to add new row
new_row = c(10, 20, 30, 40)
exam_score2= rbind(exam_score1, new_row)
exam_score2

#add new column
Location = c("cc", "dd", "ee", "ff", "gg", "jj")
exam_score2 = cbind(exam_score2, Location)
exam_score2