Question

Summarize three common rules for naming variables.

Short answer

To summarize, the three common rules for naming variables are: 1. Begin variable names with a letter or an underscore. 2. Use alphanumeric characters and underscores within variable names. 3. Do not use reserved keywords as variable names.

Step-by-step solution

Rule 1: Begin variable names with a letter or an underscore.

When naming variables, it is important to make sure that the variable name starts with either a letter or an underscore. Starting a variable's name with a number or any special character (except an underscore) is not allowed in most programming languages.

Rule 2: Use alphanumeric characters and underscores.

Variable names should only consist of alphanumeric characters (letters and numbers) and underscores. This means you should avoid using any other special characters or spaces within variable names. Using only alphanumeric characters and underscores ensures that your variable names are compatible across different programming languages.

Rule 3: Do not use reserved keywords.

In programming, certain words are reserved as keywords that serve specific purposes and cannot be used as variable names. For example, words like "if", "else", "while", "for", "function" are reserved keywords in most programming languages. When naming your variables, make sure to choose names that do not conflict with these reserved keywords to avoid any errors or unexpected behavior in your code.