A method can be defined as a group of instructions that is given a name and can be called up anywhere in the program code by simply calling it by its name. For instance, a statement to draw a straight line can be given a name straight_line. You can then call the straight_line statement thrice to draw a triangle or you could save the method triangle and call it as and when required.
All programming languages support methods presumably by different names such as functions or procedures. The Java language, just like the C++ language from which it originated, supports methods. Unlike the C++ language where an object can contain methods, the Java programming language declares a program which further contains functions known as methods. As you will notice, the method is declared in a similar manner as the method paint, the only difference being that the method paint is automatically called.
The code snippet below displays a simple method, calculate.
import java.awt.*;
import java.applet.*;
public class calculate_value extends Applet
{ int first_var, answer_var_1;
public void paint_function (Graphics graph_var)
{
First_var = 34;
Calculate_value();
g.draw_String(“Twice 46 is ” + answer_var_1, 50, 75);
}
public void calculate_value ()
{ answer_var_1 = first_var * 8;
}
}
As you can see, the method calculate_value is called by the statement calculate_value();. The syntax of the method requires the use of opening and closing braces after the method name (even they don’t contain anything) followed by a semicolon at the end.
However, it is just not enough to call a method. However, it is important to define a method before it is called. Else, the Java programming language will not know what to do when it encounters a method name. The method definition always starts with the public or private keyword. Continue reading JAVA – Methods