What is the role of the var keyword and in which situations should it be used or avoided

Question

With the help of code examples and snippets, can you tell me what the role of the var keyword is and in which situations it should be used or avoided?

Answer 1

In JavaScript, the var keyword is used to declare variables. Variables declared with var are function-scoped, meaning they are accessible throughout the entire function in which they are declared. If declared outside of any function, they become global variables.

Situations to Use or Avoid var:

Use var When:

Maintaining Legacy Code: If you're working with older JavaScript codebases that predominantly use var, maintaining consistency might be beneficial.

Avoid var When:

Writing Modern JavaScript: In ES6 and later versions, let and const are preferred for variable declarations due to their block scope and reduced risk of unintended behavior.

Preventing Scope-Related Bugs: let and const help avoid issues related to variable hoisting and scope leakage, making the code more predictable.