select() for column selection in R Programming - Mini Project: Build & Apply

Selecting Columns with select() in R

📖 Scenario: You have a small table of fruit sales data. You want to look at only some columns to understand the sales better.

🎯 Goal: Learn how to use the select() function from the dplyr package in R to pick specific columns from a data frame.

📋 What You'll Learn

Create a data frame called fruit_sales with exact columns and values

Create a vector called columns_to_select with exact column names

Use select() with fruit_sales and columns_to_select to create a new data frame

Print the new data frame

💡 Why This Matters

🌍 Real World

Selecting specific columns from data is common when you want to focus on important information and ignore the rest.

💼 Career

Data analysts and scientists often use select() to prepare data for reports, charts, or further analysis.

1

Create the fruit sales data frame

Create a data frame called fruit_sales with these exact columns and values:
Fruit: "Apple", "Banana", "Cherry"
Quantity: 10, 15, 7
Price: 0.5, 0.3, 0.8

R Programming

# Create the fruit_sales data frame with Fruit, Quantity, and Price columns
# Your code here

Need a hint?

Use data.frame() with named vectors for each column.

2

Create a vector of columns to select

Create a character vector called columns_to_select with these exact values: "Fruit" and "Price"

R Programming

fruit_sales <- data.frame(
  Fruit = c("Apple", "Banana", "Cherry"),
  Quantity = c(10, 15, 7),
  Price = c(0.5, 0.3, 0.8)
)

# Create columns_to_select vector with "Fruit" and "Price"
# Your code here

Need a hint?

Use c() to create a vector of column names.

3

Select columns using select()

Load the dplyr package with library(dplyr). Then create a new data frame called selected_data by using select() on fruit_sales with the columns in columns_to_select.

R Programming

fruit_sales <- data.frame(
  Fruit = c("Apple", "Banana", "Cherry"),
  Quantity = c(10, 15, 7),
  Price = c(0.5, 0.3, 0.8)
)

columns_to_select <- c("Fruit", "Price")

# Load dplyr and select columns from fruit_sales
# Your code here

Need a hint?

Use all_of() inside select() to select columns by name from a vector.

4

Print the selected data

Print the selected_data data frame to see only the selected columns.

R Programming

library(dplyr)

fruit_sales <- data.frame(
  Fruit = c("Apple", "Banana", "Cherry"),
  Quantity = c(10, 15, 7),
  Price = c(0.5, 0.3, 0.8)
)

columns_to_select <- c("Fruit", "Price")

selected_data <- select(fruit_sales, all_of(columns_to_select))

# Print selected_data
# Your code here

Need a hint?

Use print() to show the data frame in the console.