/*
    Variables1.java
    CIS 160
    David Klick
    2015-09-02

    Demonstration of declaring and initializing variables.
*/

public class Variables1 {
    public static void main(String[] args) {
        // Variables are named memory locations that store data.
        // We have to specify a name and data type to create a variable.
        // Java has eight built-in data types.
        
        // Declaring integer numeric variables:
        byte varByte;     // only uses one byte of storage internally
        short varShort;   // uses two bytes of storage internally
        int varInteger;   // uses four bytes of storage internally
        long varLong;     // uses eight bytes of storage internally

        // Declaring floating-point numeric variables:
        float varFloat;   // uses four bytes of storage internally
        double varDouble; // uses eight bytes of storage internally

        // Declaring character and Boolean variables:
        char varCharacter;
        boolean varBoolean;
        
        // Once a variable has been declared, you can then use it.
        // The first time a variable is set to a value,
        //     it is called "initializing the variable"
        varByte = 23;         // byte variables can only hold values from -128 through 127
        varShort = -3000;     // Data types that take more space can hold bigger ranges of values
        varInteger = -42385;  // Note: commas are NOT allowed in numbers
        varLong = -3000000;   // Note: commas are NOT allowed in numbers
        varFloat = 3.14f;     // Floating-point can have fractional parts
                              // Note: Since 3.14 would be a double, the trailing 'f' tells Java
                              // it is just a float in this case so it can be stored in varFloat.
                              // Bigger data types can not be stored in smaller data types normally.
                              // but smaller data types can be stored in bigger data types.
                              // So you can store a float in a double, but not a double in a float.
                              // It would be like trying to store a gallon of water in a pint container.
        varDouble = 0.333333; // Some numbers, such as 1/3 can't be exactly represented
        varCharacter = '?';   // char variables hold only a single character
        varBoolean = true;    // boolean variables can only be true or false
    }
}