Method & its types

Method & its types

• A method is a block of code that only runs when it is called.
• You can pass data, known as parameters, into a method.
• Methods are used to perform certain actions, and they are also known as functions.
• Why use methods? To reuse code: define the code once, and use it many times.

Where to create or defining method?

• A method must be declared within a class.
• It is defined with the name of the method, followed by parentheses ().
• Example:

System.out.println()

• Syntax:

return_type method_name ()
{
Statements;
}

• Example:

void input_data()
{
System.out.println("Hello Sarthak");
}

• Here,void means that this method does not have a return value.
• input_data() is the name of the method.
• () has no arguments.

How to calling /executing method?

• To call a method in Java, write the method's name followed by two parentheses () and a semicolon;
• Syntax:

object_name.method_name();

• Example:

s1.input_data();

• A method can also be called multiple times:

Example:
s1.input_data();
s1.input_data();
s1.input_data();

Types of methods:

1. no argument method or no-parameterized method
2. argument method or parameterized method

• Information can be passed to methods as a parameter. 
• Parameters act as variables inside the method.
• Parameters are specified after the method name, inside the parentheses. 
• You can add as many parameters as you want, just separate them with a comma.

• Syntax:

return_type method_name (arguments)
{
Statements;
}

• Example:

void input_data(String name)
{
System.out.println("Hello "+name);
}

How to call/executing parameterized method?

• To call a method in Java, write the method's name followed by two parentheses (arguments) and a semicolon;
• Syntax:

object_name.method_name(arguments);

• Example:

name="CDPatel"
s1.input_data(name);

• A method can also be called multiple times:
• Example:

name1="CDPatel"
name2="ADPatel"
name3="SDPatel"
s1.input_data(name1);
s1.input_data(name2);
s1.input_data(name3);