If a JavaScript function does not return a value, what is returned by default?

If a JavaScript function does not return a value, what is returned by default?

• A. null
• B. 0
• C. undefined
• D. false

Answer: (C)

In JavaScript, a function that doesn’t return anything finishes with an implicit return of undefined. Undefined is a special value that signals the absence of a value. It’s different from null (explicitly “no value”), 0 (a number), or false (a boolean). For example, function f() { console.log('hi'); } var result = f(); // result is undefined. typeof result is "undefined". Because there was no return statement, the function yields undefined by default.

In JavaScript, a function that doesn’t return anything finishes with an implicit return of undefined. Undefined is a special value that signals the absence of a value. It’s different from null (explicitly “no value”), 0 (a number), or false (a boolean). For example, function f() { console.log('hi'); } var result = f(); // result is undefined. typeof result is "undefined". Because there was no return statement, the function yields undefined by default.