Formal Argument v Actual Argument

Formal Argument...

Formal when declaring and the Actual is when called.

public doSomething (Frog aFrog) //Formal

dosomething(jimmy) // Actual

call a non static method from within a static method

To call a non static method from within a static method, do as below;

Exceptions in Java

ArithmeticException – an instance of this class is thrown when an exceptional arithmetic condition has occurred; for example, when integer division by zero has occurred.

NullPointerException – an instance of this class is thrown when you try to send a message to a reference variable whose value is null; that is, it does not reference an object. (The use of the word ‘pointer’ rather than ‘reference’ is a curiosity of the language, a throwback to C language terminology.)

NumberFormatException – an instance of this class is thrown to indicate that a method that converts a string to one of the numeric types has been passed an argument that does not have the appropriate format.

IndexOutOfBoundsException – an instance of this class is thrown when a program tries to access a string with an index outside the valid limits.

public static final

public static final

public static final int HOURS_IN_DAY = 24;