When a return statement is used in a function body, the execution of the function is stopped. If specified, a given value is returned to the function caller. For example, the following function returns the square of its argument, x , where x is a number.
To return a value other than the default, a function must have a return statement that specifies the value to return. A function without a return statement will return a default value. In the case of a constructor called with the new keyword, the default value is the value of its this parameter.
“Blank return” statements can be used to transfer the control back to the calling function (or stop executing a function for some reason – ex: validations etc). In most cases I use blank return statement is when I’m doing some kind of a validation.
Why does a function return undefined?
A function returns undefined if a value was not returned . Note: While you can use undefined as an identifier (variable name) in any scope other than the global scope (because undefined is not a reserved word), doing so is a very bad idea that will make your code difficult to maintain and debug.
Do functions need to return a value?
Answer. NO, a function does not always have to have an explicit return statement. If the function doesn’t need to provide any results to the calling point, then the return is not needed.
What happens when a function returns nothing?
Void functions are created and used just like value-returning functions except they do not return a value after the function executes. In lieu of a data type, void functions use the keyword “void.” A void function performs a task, and then control returns back to the caller–but, it does not return a value.
What is the difference between null and undefined?