How Do You Check What Data Type a Variable Is?

Have you ever wondered how to check the data type of a variable in your code? Knowing the data type of a variable is essential for debugging and understanding how your code is working. In this tutorial, we will explore various methods to check the data type of a variable in different programming languages.

JavaScript

JavaScript is a dynamically typed language, which means that variables can hold values of any data type. To determine the data type of a variable in JavaScript, you can use the typeof operator.

Example:

  
    let name = "John";
    console.log(typeof name); // Output: string

    let age = 25;
    console.log(typeof age); // Output: number

    let isStudent = true;
    console.log(typeof isStudent); // Output: boolean
  

Python

Python is a dynamically typed language like JavaScript. However, Python provides a built-in function called type() to check the data type of a variable.

  
    name = "John"
    print(type(name)) # Output: 

    age = 25
    print(type(age)) # Output: 

    isStudent = True
    print(type(isStudent)) # Output: 
  

C++

C++ is a statically typed language, which means that variables must be declared with their specific data types. In C++, you can use the typeid operator along with the .name() method to get the name of the data type.

  
    #include <iostream>
    #include <typeinfo>

    int main() {
        std::string name = "John";
        std::cout << typeid(name).name() << std::endl; // Output: Ss

        int age = 25;
        std::cout << typeid(age).name() << std::endl; // Output: i

        bool isStudent = true;
        std::cout << typeid(isStudent).name() << std::endl; // Output: b

        return 0;
    }
  

Ruby

Ruby is also a dynamically typed language. In Ruby, you can use the class method to check the data type of a variable.

  
    name = "John"
    puts name.class # Output: String

    age = 25
    puts age.class # Output: Integer

    isStudent = true
    puts isStudent.class # Output: TrueClass
  

Conclusion

Checking the data type of a variable is an important aspect of programming. It helps you understand how your code is working and enables you to handle different types of data appropriately. In this tutorial, we explored various methods to check the data type of a variable in JavaScript, Python, C++, and Ruby.

Remember to use these methods whenever you need to determine the data type of a variable in your code!