Just like we have some rules that we follow to speak English (the grammar), we have some rules to follow while writing a Java program. This set of these rules is called syntax. It’s like Vocabulary and Grammar of Java.
- A variable is a container that stores a value.
- This value can be changed during the execution of the program.
- Example: int number = 8; (Here, int is a data type, the number is the variable name, and 8 is the value it contains/stores).
Rules for declaring a variable name
We can choose a name while declaring a Java variable if the following rules are followed:
- Must not begin with a digit. (E.g., 1deep is an invalid variable)
- Name is case sensitive. (Sandeep and sandeep are different)
- Should not be a keyword (like Void).
- White space is not allowed. (int Code With Sandeep is invalid)
- Can contain alphabets, $character, _character, and digits if the other conditions are met.