Can you return nothing in java

Using return None

return None is never used if there are no other possible return values from the function. In the following example, we return person ‘s mother if the person given is a human. If it’s not a human, we return None since the person doesn’t have a mother (let’s suppose it’s not an animal or something).

You could change the method return type to return java.lang.Integer and then you can return null, and existing code that returns int will get autoboxed. Nulls are assigned only to reference types, it means the reference doesn’t point to anything.

Every method in Java is declared with a return type and it is mandatory for all java methods. A return type may be a primitive type like int, float, double, a reference type or void type(returns nothing). The type of data returned by a method must be compatible with the return type specified by the method.

Returning null Creates More Work

An ideal function, like an assistant cook, will encapsulate work and produce something useful. A function that returns a null reference achieves neither goal. Returning null is like throwing a time bomb into the software. Other code must a guard against null with if and else statements.

Return an Empty Array Using new int[0] in Java

To return an empty array from a function, we can create a new array with a zero size. In the example below, we create a function returnEmptyArray() that returns an array of int . We return new int[0] that is an empty array of int .

A method can return a reference to an array. The return type of a method must be declared as an array of the correct data type.

What actually does it mean when it says return -1 in this method OR any other number ? It means the author of the method does not appreciate exceptions properly. They are probably used to programming in a language like C, where clients of a method are usually notified of errors through some special return value.

2 Answers. Your code is fine. There’s no problem with returning Strings in this manner. In Java, a String is a reference to an immutable object.

You declare a method’s return type in its method declaration. Within the body of the method, you use the return statement to return the value. Any method declared void doesn’t return a value. It does not need to contain a return statement, but it may do so.

The return keyword finished the execution of a method, and can be used to return a value from a method.

In Java, return is a reserved keyword i.e, we can’t use it as an identifier. It is used to exit from a method, with or without a value.

The “missing return statement” message occurs when a method does not have a return statement. Each method that returns a value (a non-void type) must have a statement that literally returns that value so it can be called outside the method.

return 0: A return 0 means that the program will execute successfully and did what it was intended to do. return 1: A return 1 means that there is some error while executing the program and it is not performing what it was intended to do.

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. You may or may not use the return statement, as there is no return value.

In java, a method can return any type of data, including objects. For example, in the following program, the incrByTen( ) method returns an object in which the value of an (an integer variable) is ten greater than it is in the invoking object.

getch() method pauses the Output Console until a key is pressed. It does not use any buffer to store the input character. The entered character is immediately returned without waiting for the enter key. … The getch() method can be used to accept hidden inputs like password, ATM pin numbers, etc.

(1) return 0 means you are returning a integer which means at the accepting end the value gotten is 0. In case of getch(), it hold the display of the console till you press enter. (2) return 0 mean the value is return. getch() mean to keep answer in output screen.

The return statement stops execution and returns to the calling function. When a return statement is executed, the function is terminated immediately at that point, regardless of whether it’s in the middle of a loop, etc.

+1. The first void means that the main function returns no value. The second void in parenthesis (void) means that the main function accepts no arguments. The return type of main is mandated by standards to be of return type int in a hosted environment.