What is camelCase, PascalCase, kebab-case and snake_case?

Since we cannot define a variable like fruits in basket because many (or maybe all) programming languages will interpret the space character as the end of the identifier and the beginning of something else, we need to do something like fruitsInBasket.

Camel, pascal, kebab and snake case (and others) are all naming conventions that we use in computer programming to be able to create compound names for variables, types, functions, clases and other structures in source code.

camelCase

The rules are that we capitalize all the words after the first one.

Raw	camelCase
fruits in basket	fruitsInBasket
has error	hasError
is visible	isVisible

Camel case is commonly used for variables and functions in JavaScript.

PascalCase

Here we need to capitalize all the words including the first one.

Raw	camelCase	PascalCase
fruits in basket	fruitsInBasket	FruitsInBasket
has error	hasError	HasError
is visible	isVisible	IsVisible

PascalCase is often preferred by C programmers.

kebab-case

For this one, we add a dash between each word and all of them are lowercase.

Raw	camelCase	PascalCase	kebab-case
fruits in basket	fruitsInBasket	FruitsInBasket	fruits-in-basket
has error	hasError	HasError	has-error
is visible	isVisible	IsVisible	is-visible

HTML5 attributes can start with data- like data-name. Also, CSS uses dashes in property-names like background-color.

snake_case

In contrast to the kebab case, for the snake case we add an underscore instead.

Raw	camelCase	PascalCase	kebab-case	snake_case
fruits in basket	fruitsInBasket	FruitsInBasket	fruits-in-basket	fruits_in_basket
has error	hasError	HasError	has-error	has_error
is visible	isVisible	IsVisible	is-visible	is_visible

Many programmers use underscores especially in SQL databases for things like creation_date, company_name, etc.

Some benefits that naming conventions bring are:

• Consistency. Since naming something is one of the hardest jobs of a programmer, at least we can agree on a convention and be consistent about it.
• Better understanding. Compound names explain a lot better than one word or one character the purpose of the structure.
• Readability. Enhances the ability to read the code.
• Automation. Enables the use of automated refactoring and search and replace tools.