Java Methods
Methods or Functions are a block of code that accept certain parameters and perform actions whenever they are called. Methods are always written inside a Java class and can be called by simply referring to the method name.
Passing Parameters:
Parameters are nothing but the variables that are passed inside the parenthesis of a method. We can pass a single or more than one parameter of different datatypes inside our method.
Example 1: Passing single parameter
public class MethodExample {
static void Details(String name) {
System.out.println("Welcome " + name);
}
public static void main(String[] args) {
Details("Mitali");
}
}Output:
Welcome Mitali
Example 2: Passing multiple parameters
public class MethodExample {
static void Details(String name, int roll) {
System.out.println("Welcome " + name);
System.out.println("Your roll number is "+ roll);
}
public static void main(String[] args) {
Details("Mitali", 37);
}
}Output:
Welcome Mitali
Your roll number is 37
Example 3: Method with loop
public class MethodIf {
static int Details(int num) {
int fact = 1;
for (int i=2; i<=num; i++) {
fact = fact * i;
}
return fact;
}
public static void main(String[] args) {
System.out.println(Details(3));
System.out.println(Details(4));
System.out.println(Details(5));
}
}Output:
6
24
120
Example 4: Method with control statements
public class Methodloop {
static void Details(int marks) {
if (marks < 35) {
System.out.println("Fail");
} else if (marks >= 35 && marks < 65) {
System.out.println("B grade");
} else if (marks >= 65 && marks < 75) {
System.out.println("A grade");
} else if (marks >= 75 && marks < 100) {
System.out.println("O grade");
} else {
System.out.println("Invalid marks entered");
}
}
public static void main(String[] args) {
Details(25);
Details(90);
Details(60);
}
}Output:
Fail
O grade
B grade
So what can we make out from Example 3 and Example 4? In Example 3, we have created a method without using the void keyword, this lets us return the value inside the method. Whereas in Example 4, we have created a method using the void keyword, this means that our method won't return a value.