What is the main purpose of the () operator in JavaScript functions?

What does return without a value return?

A). 0

B). null

C). undefined

D). NaN

What happens if a function is invoked without parentheses in an event handler like onclick='myFunction'?

A). The function is executed immediately

B). The function reference is assigned

C). An error is thrown

D). The function does not work

What is the output of function sayHi() { return 'Hi'; } alert(sayHi());?

A). sayHi

B). Hi

C). undefined

D). alert

What is the output of function multiply(x, y) { return x * y; } var result = multiply(5, 10); console.log(result);?

A). 50

B). 510

C). undefined

D). multiply

What is the result of invoking a function without parentheses, like myFunction?

A). The function gets executed

B). The function returns undefined

C). The function is referenced but not executed

D). The function throws an error

Which of these is the correct way to define and immediately invoke a function?

A). function() { return 1; };

B). (function() { return 1; })();

C). function() { return 1; }();

D). function {}()

What does return do inside a function?

A). Stops the function

B). Returns a value to the caller

C). Both A and B

D). Declares a variable

What will function greet() { console.log('Hi'); } var x = greet; x(); output?

A). Hi

B). undefined

C). x

D). greet

What is the output of function test() { return 2 + 2; } console.log(test());?

A). 22

B). 2 + 2

C). 4

D). test

How do you define and invoke a function to calculate the square of a number in one step?

A). var square = function(n) { return n * n; }; square(5);

B). (function(n) { return n * n; })(5);

C). function square(n) { return n * n; } square(5);

D). var square = (n) { return n * n; }; square(5);