Basic Concept of Method In java


Introduction to the method

A method is a set of code which is referred to by name and can be called (invoked) at any point in a program simply by utilizing the method's name.  It is also called as sub-program/function it often returns value.
The method has its own name.  When that name is called in a program, the execution of the program goes inside the body of that method.  When the method is finished executing, it returns to the area of the program from which it was called, and the program continues on to the next line of code.

Process of calling method is given below: -
Good programmers write in a modular fashion which allows for several programmers to work independently on separate concepts which can be assembled at a later date to create the entire project.  The use of methods will be our first step in the direction of modular programming.
Methods are time savers; in that, they allow for the repetition of sections of code without retyping the code.  In addition, methods can be saved and utilized again and again in newly developed programs.

You are using the method when you write the code
 System.out.print( ) and System.out.println( ).
There are two basic types of methods: 

Built-in:  Build-in methods are part of the compiler package, such as System.out.println( ) and  System.exit(0).
 
User-defined: User-defined methods are created by the programmer. These methods take-on names that programmer assign to them and perform tasks that they are created for.

How to invoke (call) a method (method invocation):

When a method is called(invoked), a request is made to perform some action, such as setting a value, printing statements, returning an answer, etc.  The code to invoke the method contains the name of the method to be executed and any needed data that the receiving method requires.  The required data for a method is specified in the method's parameter list.
Consider this method that we have already been using from Breezy;
      String str = str1.toUpperCase(); //Converts all string contained in str1 to Upper class and store in variable str.
The method name is .toUpperCase() which is defined in the class “String”.  Since the method is defined in the class String, we must call String class before coding in current class.  This particular method returns all the lowercase letter contained in the str1 variable is converted in uppercase and stored in str variable.
You invoke (call) a method by writing down the calling object followed by a dot, then the name of the method, and finally a set of parentheses that may (or may not) have information for the method.

Comments

Post a Comment

Popular posts from this blog

Java Program to make a comparison between numbers

Conversion between Numbers public class Double Comparison {         public static void main (String []args)        {                   boolean  result;  //declaring  variable               int a=30 , b=27 ;  //value assign                result = (a>=b)&&(b>=a);  //comparison                System.out.println ("is (30>=27)and(27>=30) ? "+result);  //output                result = (a>=b)||(b>=a); //comparison                System.out.println ("Is (30>=27)or(27>=30) ? "+result);  //output          } }  Output of the given program is :- Is (30>=27)and(27>=30) ? false  Is (30...
Read more

Java program using Scanner Class

Scanner Class in Java The scanner is a class in java.util package used for obtaining the input of the primitive types like int, double, etc. and strings. It is the easiest way to read input in a Java program, though not very efficient if you want an input method for scenarios where time is a constraint like in competitive programming. To create an object of Scanner class, we usually pass the predefined object System.in, which represents the standard input stream. We may pass an object of class File if we want to read input from a file. To read the numerical values of a certain data type XYZ, the function to use is nextXYZ(). For example, to read a value of type short, we can use nextShort() To read strings, we use nextLine(). To read a single character, we use next().charAt(0). next() function returns the next token/word in the input as a string and charAt(0) funtion returns the first character in that string Program to calculate import java.util.Scanner; //Calli...
Read more

Java program to print 'Hello World'

Simple program to print 'Hello World' This is the starting phase of the java program to print "Hello World". You can change the sentence inside the double quote sign like:- "Hello World" to "Hii This is my first java program", or anything according to your wish. public class  PrintHello {                public static void main(String []args)       {                              System.out.println (" Hello World  "); //Printing Hello                     } } Output of the above program is:  Hello World
Read more