What is the maximum length of an identifier?
A). 255 characters
B). 31 characters
C). 64 characters
D). No limit
Which of the following is a valid identifier name?
A). var
B). 123abc
C). _123abc
D). #abc123
Which is a correct identifier for a variable?
A). 9variable
B). variable-9
C). variable_9
D). variable 9
What is the output of the following code: var x = 5, x = 10;
A). Syntax error
B). 5
C). 10
D). Reference error
Which of the following is an invalid identifier?
A). _variable
B). var$
C). 2variable
D). variable2
Which characters are allowed in JavaScript identifiers?
A). Letters only
B). Letters and numbers only
C). Letters, numbers, $ and _
D). Any special characters
What will the following code output: var x; x = 5; var y = x;
A). undefined
B). null
C). 5
D). x
Which of these is an invalid identifier?
A). foo_bar
B). fooBar
C). foo-bar
D). foo$bar
What is a valid identifier in JavaScript?
A). 123abc
B). abc123
C). let
D). var
Are JavaScript identifiers case-sensitive?
A). Yes
B). No
C). Only in ES6
D). Only in strict mode