COMPUTER FUNDAMENTALS

Detailed explanation-1: -Specifically, spaces are not permitted in the variable names, as the variable name must be a single word. The variable name may not start with a digit or underscore, and may not end with an underscore. Double underscores are not permitted in the variable names. Hence the correct answer is White space characters.

Detailed explanation-2: -White space is not permitted. This is forced from language designing. Compiler needs to find out the meaning of words. Compiler works on a “State Machine” method, and it needs to distinguish key words. Maybe placing variable names in “[” and “]” give us some solution(like SQL).

Detailed explanation-3: -Explanation: We can insert blank spaces between two words to improve the readability of the statement but no blank spaces are allowed within a variable, constant or keyword. The keywords cannot be used as variable names.

Detailed explanation-4: -Variable name may not start with a digit or underscore, and may not end with an underscore. Double underscores are not permitted in variable name.