Question

[A] Which of the following are invalid C constants and why?
'3.15
35,550 3.25e2
2e-3
'eLearning' "show"
'Quest'
4652

[B] Which of the following are invalid variable names and why?
int
B'day
#HASH
totalArea
total%
variable name
dot.
_main()
1st
%name%
Shello
number
temp_in_Deg
stack-queue
salary​

Answer 1

Answer:

Which of the following are invalid C constants and why?

'3.15

35,550 3.25e2

2e-3

'eLearning' "show"

'Quest'

4652

Answer 2

A.

• '3.15
• 35,550 3.25e2
• 2e-3
• 'eLearning' "show"  these are invalid C constants

• 'Quest'
•  4652   these are valid Constants  

How to check whether it is a valid constant or invalid?

• An integer constant consists of a sequence of Integer numbers from 0 to 9
• Decimal points, black spaces, and commas cannot be included within an integer constant.
• An Integer constant can either be positive or negative or zero.
• The number without a sign can be assumed a positive

B.

• int                  
• B'day  
• #HASH
• stack-queue
• %name%
• total%
• variable name
• dot.
• _main()

these are invalid variables, remaining are valid variables because ypu can check the below points;

How to check whether it is a valid Variable or invalid?

• A variable cannot start with a number or numeric value like 1,2,3 etc.
• No special characters can be used other than underscore(_). For eg:- ×*%#@ ., are prohibited in variable names.
• A variable can only start with an underscore or an alphabet(uppercase and lowercase both are both included).
• #SPJ2