What happens when you try to access a variable that has not been declared in JavaScript?
A). SyntaxError is thrown
B). ReferenceError is thrown
C). TypeError is thrown
D). Undefined
What is the result of the expression undefined + null in JavaScript?
A). undefined
B). null
C). 0
D). Error
Which of the following is a primitive data type in JavaScript?
A). Array
B). Object
C). Function
D). String
Which symbol is used to represent a boolean value in JavaScript?
A). #
B). $
C). !
D). true/false
What is the result of the expression true == 1 in JavaScript?
A). true
B). false
C). Error
D). 1
What is the default value of a variable in JavaScript if it is not initialized?
A). null
B). undefined
C). 0
D). 'undefined'
What is a primitive value in JavaScript?
A). A complex data structure
B). A basic data type
C). A function
D). An array
Which primitive value represents absence of value or no value assigned?
A). undefined
B). null
C). 0
D). 'undefined'
What is the result of the expression true + false in JavaScript?
A). true
B). false
C). 1
D). 0
Which of the following is a valid way to represent the value null in JavaScript?
A). undefined
B). NULL
C). null
D). None of the above