Which are valid c# veriable name?

Answer 1

C# like any programming languages is case sensitive language, been said that here are some arbitrary rules for valid variable name
1. A variable name must always start with an alphabet. (except one exception)
2. A variable name cannot start with number, a number can appear anywhere in variable name except at the starting.
3. no special character is allowed in a variable name except underscore (_) sign.
4. a variable name can however start with underscore.
5. a variable name should not contain white space.

so all variable names that follow above rules are valid variable name.

Answer 2

Your first letter in a variable name must be small letter if you want to combine two words, e.g myName

Answer 3

if it's start with a letter

Answer 4

must start with a letter or underscore