Java identifiers

Identifiers are the name given to variables, classes, methods, etc. Consider the above code; 2.3.3. Here, $\lstinline{score}$ is a variable (an identifier). You cannot use keywords as variable names. It's because keywords have predefined meanings. For example,

The above code is wrong. It's because $\lstinline{float}$ is a keyword and cannot be used as a variable name.