/*
VariableExample.java 
Examples of creating and assigning variables of different types
including casting and some expressions
 */
 
package pkg119_02_variables.variableEx;

public class VariableExample {
    
    public static void main(String[] args) {
    
        // ints are integers, 32 bits
        // declare variable 
            // whose type is int
            // and whose name is x
        int x; 
        int highestInt;
        int numPuppies;

        // assign variable
            // store number 3 in x
            // variable is LHS
            // value is RHS
        x = 3;
        highestInt = 2147483647;

        // x = 7.9;  // has fractional part
        //numPuppies = 2147483650; // too big

        // declare and assign variable in one line
        int y = -91;
        
        
        
        
        
        // other integer types
        byte b = 127;                       // 8 bits
        short s = 32767;                    // 16 bits
        // long values have L at the end
        long l = 922337203685477580L;       // 64 bits

        
        
        // double -- 64 bits
        double d = 1.2;
        d = 44488.0;
        d = -5.5;
        double veryBig = 179769313486231570000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000.0; 
        double verySmall = .00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001;
        // exponential notation allows very big or small numbers
        d = 5.5E5;  5.5 * 10^5 = 550000
        d = 5.5E-5;  5.5 * 10^-5 = 0.000055

        
        // float -- 32 bits
        // float values have f at the end
        float f = 3.4028235E38f; // 3.4... * 10^38
        float f2 = 340282350000000000000000000000000000000f; // same number
        float smallfloat = 1.4E-45f;



         // boolean for true and false
        boolean numWasBig;
        numWasBig = true;
        boolean scary = false;
        
        // char for single character
        char lettera = 'a';
        char letterA = 'A'; // different variable name and value!!
        char space = ' ';
        //char noLetters = ''; // error! every char is exactly 1 letter/number/punctuation mark long, 0 is not 1
        
        // String for text
        String str = "the quick brown fox jumps over the lazy dogs";
        String stringa = "a"; // single character a
        String stringSp = " "; // single character space
        String emptyString = ""; // zero characters is fine for String
        
        
        // java checks types on assignment -- these are errors
        //int badint = 4.6;         // double not okay for int
        //boolean  badbool = 3;     // int not okay for boolean
        //double baddoub = "hello"; // string not okay for double
        //String badstr = 99.33;      // double not okay for String
        
        
        
        // type casting

        // implicit cast
        
        int isInt = 9;
        // int implicitly converted into double -- add .0 onto end
        double isDoub = isInt;
        isDoub = 123;

        // implicit cast happens for operations + - * / % 
        double result = isInt + isDoub;

        
        // explicit cast
        
        // errors - double not autmatically converted into int
        // because we might be losing something
        //isInt = 5.5;
        //isInt = 5.0;          // still error, even though there's actually nothing to lose
        //isInt = isDoub;
        
        // explicitly cast double to int
        // throw away fractional part
        isInt = (int)5.5;		// now 5.0
        isInt = (int)isDoub;
        
        // integer division fixed with explicit casting
        int numerator = 22;
        double answer = numerator / 3; // integer division gives 7
        answer = numerator / 3.0;       // fixed, using a double
        answer = (double)numerator / 3; // fixed, cast to a double before division
        answer = (double)(numerator / 3); // not fixed -- casting after integer division
        
        
    }
    
}