How Do You Define and Use Constants in JavaScript?

Exploring Constants in JavaScript

In JavaScript, constants are immutable values that remain consistent throughout the execution of a program. While the language didn't initially support constants, the introduction of ES2015 brought forth the const keyword.

Using the const Keyword

To define a constant using the const keyword, simply assign the desired value to a variable declared with const. For example:

const MY_CONSTANT = "some-value";

This will create a constant named MY_CONSTANT with the value "some-value."

Browser Compatibility and Conventions

The const keyword is widely supported in modern browsers. However, older versions of Internet Explorer (IE 8, 9, and 10) do not support this feature. To ensure compatibility with these browsers, you can use the var keyword instead.

When using var to represent constants, adopt conventions such as writing variable names in all capital letters. This helps developers recognize that these values should not be modified:

var ALL_CAPS_CONSTANT = "some-value";

Conclusion

The introduction of the const keyword in JavaScript simplifies the process of defining constants and enhances code readability. While older browsers may require the use of var with conventions, the const keyword is the preferred method for declaring constants in modern JavaScript applications.

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