Popular Naming Conventions for Variables: Snake Case, Pascal Case, Camel Case

Snake Case

var snake_case;

The expression style that includes underscores (_) is called snake case, named after the appearance of a snake.

Pascal Case

var PascalCase;

When the first letter and the middle letters are capitalized, it is similar to the notation used in the Pascal language, and it is called the Pascal case.

Camel Case

var camelCase;

When the middle letters are capitalized but the first letter is lowercase, it resembles the shape of a camel, so it is called a camel case.