R:向量中的元素计数。Count()不起作用

vector <- c("apple", "banana", "apple", "orange", "banana")
count_result <- count(vector)
print(count_result)

# A tibble: 3 x 2
  value   n
  <chr> <int>
1 apple     2
2 banana    2
3 orange    1

df <- data.frame(fruit = c("apple", "banana", "apple", "orange", "banana"))
count_result <- count(df, fruit)
print(count_result)

# A tibble: 3 x 2
  fruit      n
  <chr>  <int>
1 apple      2
2 banana     2
3 orange     1