Which data type represents a block of reusable code in JavaScript?
A). String
B). Object
C). Function
D). Number
What will the following code snippet output: let a = 10; a += '5'; console.log(a); in JavaScript?
A). '105'
B). 105
C). 15
D). '15'
What is the data type of the value 42 in JavaScript?
A). String
B). Boolean
C). Number
D). Null
What is the data type of the value true in JavaScript?
A). Number
B). String
C). Boolean
D). Undefined
Which of the following is not a valid data type in JavaScript?
A). Array
B). Symbol
C). Map
D). Tuple
What is the outcome of typeof [1, 2, 3] in JavaScript?
A). String
B). Number
C). Array
D). Object
Which data type represents positive infinity in JavaScript?
A). Infinity
B). Number
C). NaN
D). Null
What is the data type of the value undefined in JavaScript?
A). Number
B). Boolean
C). String
D). Undefined
Which data type represents an intentional absence of any value in JavaScript?
A). Null
B). Undefined
C). String
D). Number
Which data type represents unique and immutable values in JavaScript introduced in ES6?
A). Symbol
B). Object
C). Array
D). Function