What is dynamic typing?

Overview

The term dynamic typing means that a compiler or an interpreter assigns a type to all the variables at run-time. The type of a variable is decided based on its value.

The programs written using dynamic-typed languages are more flexible but will compile even if they contain errors.

Let’s see some examples to understand how dynamic-typed languages differ from static-typed languages.

Example 1

Let’s first see how static-typed languages work:

class Main {
    public static void main( String args[] ) {
      int number;
      number = 10; 
      System.out.println(number);
    }
}

Explanation

In static-typed languages, we have to define the type of a variable before we assign a value to it.

In the code above:

  • Line 3: We declare a variable number. Note that we have also defined its type here.
  • Line 4: We assign a value to the variable number.
  • Line 3: We print the value of the variable number on the console.

Example 2

Now let’s see how dynamic-typed languages work:

number = 10
print(number)

Explanation

In dynamic-typed languages, we don’t need to define the type of a variable as an interpreter at run-time will handle it.

In the above code: Line 1: We declare a variable number and assign a value to it. Note that we have not defined its type here.

Line 2: We print the value of variable number on the console.

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