20 Jul Java Methods
A method is an organized block of reusable code that avoids repeating tasks again and again. If you want to do a task repeatedly in code, then just make a method, set the task in it, and call the method multiple times whenever you need it. Methods are also known as Functions.
Types of Methods in Java
The following are the types of methods:
- Pre-defined: Eg: println(), concat(), equals(), etc.
- User-defined: Custom methods created by the programmer for custom tasks.
Let us see how to:
- Create and call a method.
- Method Declaration and Definition
- Method Parameters
- Multiple Parameters
Create and call a Method in Java – Example 1
To create a function in Java, set the name of the function followed by parentheses. Our method is demoMethod():
public static void demoMethod() {
// write the code
}
A function in Java gets executed when it is called:
demoMethod()
Let us now see an example of creating a method in Java:
// Create and call a Function (Method) in Java
class Studyopedia {
/* We add the static keyword in Java so that a method belongs to the class itself,
rather than to individual objects created from that class */
/* A static method is tied to the class itself. Even if no object of Demo105 exists,
the method can still be executed.
*/
// Function Definition
static void demoMethod() {
System.out.println("This is a demo method in Java.");
}
public static void main(String[] args) {
// Function call
demoMethod();
}
}
Output
This is a demo method in Java.
Method Declaration and Definition
In the above example, we saw how to create and call a method in Java. We defined and declared the method as well:
public static void demoMethod() { // method declaration
// method definition
}
A method in Java gets executed when it is called:
demoMethod()
Method Parameters in Java – Example 2
Set the parameters in a Java method after the name of the method. For example:
static void demoMethod(int rank) { }
To call a method with a parameter, set the value of the variable while calling, for example:
demoMethod(5)
Therefore, we have passed the rank with the value 5 while calling the above.
Let us now see an example of creating a Method and passing a parameter in Java:
// Function (Method) Parameters in Java
class Studyopedia {
/* We add the static keyword in Java so that a method belongs to the class itself,
rather than to individual objects created from that class */
/* A static method is tied to the class itself. Even if no object of class Studyopedia exists,
the method can still be executed.
*/
// Function Definition with rank parameter
static void demoMethod(int rank) {
System.out.println("This is a demo method in Java.");
System.out.println("Rank = "+rank);
}
public static void main(String[] args) {
// Function call with 5 as an argument
demoMethod(5);
}
}
Output
This is a demo method in Java. Rank = 5
Multiple Parameters in a Method in Java
We can also set more than one parameter in a function in Java. For example:
static void demoMethod(string player, int rank, int points)
To call a function with multiple parameters, set the value of the variable while calling, for example:
demoMethod("Amit", 1, 95)
We have passed the following multiple parameters while calling the above:
- player: Amit
- rank: 1
- points: 95
Let us now see an example of creating a Method and passing multiple parameters:
// Function (Method) with Multiple Parameters in Java
class Demo107 {
/* We add the static keyword in Java so that a method belongs to the class itself,
rather than to individual objects created from that class */
/* A static method is tied to the class itself. Even if no object of Demo105 exists,
the method can still be executed.
*/
// Function Definition with player, rank, and points parameter
static void demoMethod(String player, int rank, int points) {
System.out.println("\nThis is a demo method in Java.");
System.out.println("Player = "+player);
System.out.println("Rank = "+rank);
System.out.println("Points = "+points);
}
public static void main(String[] args) {
// Function call with 3 arguments
demoMethod("Amit", 1, 95);
demoMethod("Steve", 2, 90);
demoMethod("David", 3, 80);
}
}
Output
This is a demo method in Java. Player = Amit Rank = 1 Points = 95 This is a demo method in Java. Player = Steve Rank = 2 Points = 90 This is a demo method in Java. Player = David Rank = 3 Points = 80
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