What is the output of the following code: var x = 5, x = 10;
A). Syntax error
B). 5
C). 10
D). Reference error
Which identifier is valid in strict mode?
A). public
B). _public
C). 123public
D). public$
Which of the following is a valid identifier name?
A). var
B). 123abc
C). _123abc
D). #abc123
Which of these is an invalid identifier?
A). foo_bar
B). fooBar
C). foo-bar
D). foo$bar
Is let a valid identifier in JavaScript?
A). Yes
B). No
C). Only in ES6
D). Only in non-strict mode
Are JavaScript identifiers case-sensitive?
A). Yes
B). No
C). Only in ES6
D). Only in strict mode
Can JavaScript identifiers include spaces?
A). Yes
B). No
C). Only in ES6
D). Only in strings
Can identifiers start with a digit in JavaScript?
A). Yes
B). No
C). Only in ES5
D). Only in strict mode
Which of the following is an invalid identifier?
A). _variable
B). var$
C). 2variable
D). variable2
What does the following code do: var $ = 5;
A). Throws an error
B). Creates a variable named $
C). Creates a variable named var
D). None of the above