How can you convert a string to a number in JavaScript?
A). parseInt('10')
B). parseFloat('10.5')
C). Number('10')
D). All of the above
How do you concatenate strings in JavaScript?
A). Using the + operator
B). Using the - operator
C). Using the * operator
D). Using the / operator
What is the correct way to declare a JavaScript class?
A). class Rectangle {}
B). let Rectangle = {}
C). function Rectangle() {}
D). Rectangle {}
What is the purpose of the 'return' statement in a JavaScript function?
A). To end the function execution
B). To return a value from the function
C). To print a value to the console
D). To declare a variable
Which statement correctly declares a JavaScript arrow function?
A). const add = (a, => a + b;
B). function add(a, { return a + b; }
C). const add = function(a, { return a + b; }
D). let add = function(a, { return a + b; };
What is the purpose of the 'this' keyword in JavaScript?
A). To refer to the current HTML element
B). To refer to the current JavaScript file
C). To refer to the current object
D). To refer to the current function
What is the purpose of the 'typeof' operator in JavaScript?
A). To check if a variable is defined
B). To check the data type of a variable
C). To assign a data type to a variable
D). To increment the value of a variable
What does the '===' operator check in JavaScript?
A). Type and value equality
B). Type equality only
C). Value equality only
D). Reference equality
What is the purpose of the 'break' statement in a JavaScript switch case?
A). To continue to the next case
B). To exit the switch statement
C). To restart the switch statement
D). To execute the default case
How can you comment a single line of code in JavaScript?
A). // This is a comment
B). <!-- This is a comment -->
C). /* This is a comment */
D). ''' This is a comment '''