Video Materials

Methods are a very useful way to divide our code into smaller chunks. However, many times we need to provide input to our methods. This allows us to reuse the same code, but with different values each time we call the method. So, let’s review how to add parameters to our methods in Java.

Method Parameters

In Java, we can add parameters to a method declaration by placing them in the parentheses () at the end of the declaration. Each parameter is similar to a variable declaration, requiring both a type and an identifier. We can also define multiple parameters, separated by commas ,.

For example, let’s extend our definition of foo() from the previous page by adding a String parameter named message:

static void foo(String message){
    System.out.println("Message: " + message);

Then, when we call that method, we are required to provide an argument of the correct type. That argument will be stored as the parameter’s variable in foo():

foo("Hello World!");

Another Example

Here’s another example. In this case, we are writing two methods, foo() and bar(). They accept multiple parameters, and in main() we call each method using arguments for each parameter.

public class Parameters{
    public static void main(String[] args){
        int x = 5;
        int y = 10;
        int z = 8;
        bar(x, y, z);
        foo(y, true);
    static void foo(int output, boolean longMessage){
            System.out.println("The value was " + output);
            System.out.println("Val: " + output);
    static void bar(int a, int b, int c){
        System.out.println(a + ", " + b + ", " + c);

First, let’s look at bar(). When we call this method from main(), we are using x, y, and z as arguments. So, inside of bar(), the value stored in x will be stored in a, y will be stored in b, and z will be stored in c. The parameters and arguments are matched up based on the order they are provided to the method call. So, bar() will output 5, 10, 8 when it is called with those parameters.

The call to foo() is very similar. It only contains two parameters, but each one is a different type. So, when we call that method, we must make sure that the first parameter is an integer, and the second one is a Boolean value.