Exploring table metadata

After creating the weather data table, the meteorological team needs to understand its structure before generating their reports. The team leader has asked you to provide information about the table's dimensions, columns, and a preview of the data.

The Table, DoubleColumn, and StringColumn classes from Tablesaw have been imported for you.

This exercise is part of the course

Importing Data in Java

Exercise instructions

Print the table dimensions.
Display the column names.
Print the table structure.
Preview the first three rows.

Hands-on interactive exercise

Have a go at this exercise by completing this sample code.

public class WeatherMetadataExample {
    public static void main(String[] args) {
        StringColumn days = StringColumn.create("Day", 
            "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday");
            
        DoubleColumn temperatures = DoubleColumn.create("Temperature", 
            22.5, 24.0, 23.2, 21.5, 20.8, 25.1, 26.3);
            
        DoubleColumn precipitation = DoubleColumn.create("Precipitation", 
            0.0, 2.5, 5.2, 0.0, 0.0, 1.3, 0.0);
        
        Table weatherData = Table.create("WeatherData")
            .addColumns(days, temperatures, precipitation);
        
        // Print the table dimensions
        System.out.println(____.____());
        
        // Display the column names
        System.out.println(____.____());
        
        // Print the table structure
        System.out.println(____.____());
        
        // Preview the first three rows
        System.out.println(____.____(____));

    }
}

Edit and Run Code

This exercise is part of the course

Importing Data in Java

IntermediateSkill Level

5.0+

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Kickstart your journey into data handling with Java! In this first chapter, you'll learn how to read, validate, and manage data using Java I/O Streams and then dive into the powerful Tablesaw library to easily create, explore, and manipulate data tables, the perfect foundation for modern data analysis in Java.

Exercise 1: Understanding Data Import Fundamentals Exercise 2: Creating basic file readers Exercise 3: Implementing data validation Exercise 4: Java I/O Streams overview Exercise 5: Reading files with BufferedReader Exercise 6: Writing files with BufferedWriter Exercise 7: Stream chaining Exercise 8: Introduction to Tablesaw Exercise 9: Creating a table Exercise 10: Exploring table metadata

Current Exercise

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Complete your Java data journey by mastering transformation patterns that allow you to modify columns, process rows, and summarize datasets into meaningful insights. You’ll also work with JSON data, from simple files to complex, nested structures - preparing you to handle modern APIs and configuration files.

Exercise 1: Data Transformation Patterns Exercise 2: Employee salary analysis Exercise 3: Total compensation calculator Exercise 4: Department summary statistics Exercise 5: JSON Data Basics with Tablesaw Exercise 6: Loading JSON files Exercise 7: JSON data analysis Exercise 8: JSON validation Exercise 9: Complex JSON Processing Exercise 10: Importing nested data Exercise 11: Merging nested data Exercise 12: Handling missing JSON values Exercise 13: Congratulations!