CODEWITHSUNDEEP
javareturn-valuereturn
user2338180
user2338180

Reputation: 67

What does it mean to return a value?

I'm fairly new to programming, and I'm confused about what it means exactly to return a value. At first, I thought it meant to output what value is being returned, but when I tried that in my own code, nothing happened. 

class Class1 {

    public static int x = 3;

    public static int getX(){
        return x;
    }

    public static void main(String[] args){
        Class1.getX();
    }
}

This is an example of what I mean. When I run the program, nothing shows up. Considering this, I'm led to believe returning a value means something else. But what?

Upvotes: 3

Views: 58795

Answers (4)

user23254255
user23254255

Reputation: 1

What it means is that you invoke a function (any function) and the result of the function is passed back to the code that called it.

For example if you have a method called add and you invoke that method the value returned will be assigned to the calling code, please see the example below.

public class Main { 

    public static void main(String[] args) {
        int a = 10;
        int b = 20;
        // Function add is called with two values and the result is assigned to 
        // the variable z
        int z = add(a, b); 
        System.out.println("The sum of a and b is: " + z);
        }

    static int add(int a, int b){
        int z = a+b;
        return z;

    }
}

Upvotes: 0

Zim-Zam O'Pootertoot
Zim-Zam O'Pootertoot

Reputation: 18148

Returning a value is a way for methods to talk to each other

public void method1() {
    int value = 5 + method2(5);
    System.out.println(value);
}

public int method2(int param) {
    return param + 5;
}

This will print 15 (5 gets sent to method2, which adds 5 to it and returns the result to method1, which adds 5 to it and prints the result).

Java returns copies of values - in this case, it's copying the value 10 and returning it to method1. If method2 were returning an Object then it would return a copy of the object's reference. Different languages have different semantics for method returns, so be cautious when switching between languages. Java also copies the values of parameters passed to methods - in this case method1 copies the value 5 and passes it to method2.

public void method1() {
    int value = 5;
    method2(value);
}

public void method2(int param) {
    param = param + 5;
}

The value in method1 is unaffected by method2 (value still equals 5 after method2 executes), because only a copy of value was sent as a parameter.

Upvotes: 2

Juned Ahsan
Juned Ahsan

Reputation: 68715

You are just calling a method which returns an integer but you are never using/printing it. Try to use it in your code to see whether you have got the desired value as you have set in your class.

Upvotes: 0

MadProgrammer
MadProgrammer

Reputation: 347194

In simple terms, it means to return the value to caller of the method...

So, in your example, the method getX would return the value of x to the caller, allowing them access to it.

class Class1{

    static int x = 3;

    public static int getX(){
        return x;
    }

    public static void main(String args[]){
        int myX = Class1.getX(); // return the value to the caller...
        System.out.println(myX); // print the result to the console...
    }
}

Upvotes: 7

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