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 does NaN represent in JavaScript?
A). Not a Number
B). Infinity
C). Positive Infinity
D). Negative Infinity
Which data type represents a block of reusable code in JavaScript?
A). String
B). Object
C). Function
D). Number
What is the outcome of typeof [1, 2, 3] in JavaScript?
A). String
B). Number
C). Array
D). Object
What will let x = null; console.log(typeof x); output in JavaScript?
A). Object
B). Null
C). Undefined
D). Number
Which of the following is a primitive data type in JavaScript?
A). Object
B). Array
C). Function
D). Boolean
What is the data type of the value 42 in JavaScript?
A). String
B). Boolean
C). Number
D). Null
What will be the result of typeof 'hello' in JavaScript?
A). String
B). Number
C). Undefined
D). Function
Which data type represents an intentional absence of any value in JavaScript?
A). Null
B). Undefined
C). String
D). Number
Which of the following is not a valid data type in JavaScript?
A). Array
B). Symbol
C). Map
D). Tuple