Methods without returning any value
and without parameters
Syntax:
void methodName(){
//body
}
If a method don't return any value, then it's return type must be void
Example
class MethodEx{ void print(){ System.out.println("I am not returning any value"); } public static void main(String args[]){ MethodEx obj = new MethodEx(); obj.print(); } }
Output
I am not returning any value
Methods without returning any value
and with parameters
Syntax:
void
methodName(parameters){
//body
}
You can give any number of
parameters to a method
Example
class MethodEx{ void print(int a, int b){ System.out.println("The parameter value is " + a +" " + b); } public static void main(String args[]){ MethodEx obj = new MethodEx(); obj.print(10,20); } }
Output
The parameter value is 10 20
Methods with returning a value and
without parameters
Syntax
returnType methodName(){
//body
}
Here returnType is any
primitive or reference type. The method must returns the value which
is compatible with the returnType of the method.
Example
class MethodEx{ String fun(){ return "Let's have fun with methods"; } public static void main(String args[]){ MethodEx obj = new MethodEx(); String s = obj.fun(); System.out.println(s); } }
Output
Let's have fun with methods
Observation
The method fun() return type is
String, so whatever the value returns by the method fun(), we must
store it in the String variable like “String s = obj.fun()”.
Methods with returning a value and
with parameters
Syntax
returnType
methodName(parameters){
//body
}
A method can have any number of
parameters. Here returnType is any primitive or reference type. The
method must returns the value which is compatible with the returnType
of the method.
Example
class MethodEx{ String fun(String firstName, String lastName, int age){ return "I am " + firstName +" " + lastName + " and my Age is " + age; } public static void main(String args[]){ MethodEx obj = new MethodEx(); String s = obj.fun("Aravind", "Phaneendra", 25); System.out.println(s); } }
Output
I am Aravind Phaneendra and my Age is 25
Some
Points to Remember
1.
returning incompatible value causes the compiler to throw error.
Example
class MethodEx{ int sum(int a, int b){ return 10.01; } }
When you try to compile the above
program, compiler will throw the below error
MethodEx.java:4: error: possible loss of precision return 10.01; ^ required: int found: double 1 error
2. You can call the method in
print methods, if it is returning a value, i.e, non void type methods
Example
class MethodEx{ int sum(int a, int b){ return (a+b); } public static void main(String args[]){ MethodEx obj = new MethodEx(); System.out.println("Sum of 10 and 20 is " + obj.sum(10,20)); } }
Output
Sum of 10 and 20 is 30
3. Calling void methods inside
the print causes compile time error
Example
class MethodEx{ void print(){ } public static void main(String args[]){ MethodEx obj = new MethodEx(); System.out.println(obj.print()); } }
When you try to compile the above
program, compiler will throw the below error.
MethodEx.java:7: error: 'void' type not allowed here System.out.println(obj.print()); ^ 1 error
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