Dynamic typing, also known as dynamic type checking, is a programming language feature where variables are not explicitly declared with a data type. Instead, the type of a variable is determined at runtime based on the value assigned to it. This allows for more flexibility but can lead to runtime errors if types are not handled correctly.
In dynamically typed languages, the type of a variable can change as the program runs. For example, a variable initially assigned an integer value can later be assigned a string value without causing a compilation error. This flexibility simplifies coding but can make it harder to catch certain types of errors early in the development process.
Example in JavaScript: JavaScript is a dynamically typed language. Here’s an example demonstrating dynamic typing:
let x = 10; // x is now a number
console.log(typeof x); // Outputs: number
x = "Hello"; // x is now a string
console.log(typeof x); // Outputs: string