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 '''
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 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
How can you prevent a JavaScript function from executing immediately?
A). Using async/await
B). Using the defer attribute in HTML script tag
C). Wrapping the function in parentheses
D). Using the setTimeout function
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 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 '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
What is the correct way to declare a JavaScript class?
A). class Rectangle {}
B). let Rectangle = {}
C). function Rectangle() {}
D). Rectangle {}
How do you concatenate strings in JavaScript?
A). Using the + operator
B). Using the - operator
C). Using the * operator
D). Using the / operator
Which statement correctly declares a JavaScript function?
A). function greet() {}
B). const greet = function() {}
C). const greet = () => {}
D). const greet = {}