java.util.Scanner ---> interactive programs
nextLine()
nextDouble()
nextInt()
nextFloat()

scan.nextFloat()

java.lang.String ---> sequence of characters

java.util.Random ---> generate both discrete and continuous random variates
nextInt(upper)
nextInt()
nextFloat()

rnd.nextFloat()

Connecting a method call to the right method definition: method binding

- java.lang.Math

int val = Math.pow(2, 3); // Invalid statement

If the method is static, then it can be used through the class name

Math.pow(2, 3); // 8.0
Math.pow(4, 0.5); // 2.0
Math.pow(4, 1/2); // 1.0

Math.sqrt(9); // 3.0

Math.abs(-3); // 3

Math.ceil(4.5); // 5.0
Math.floor(4.5); // 4.0

Math.cos, Math.sin: angle is measured in radians

Math.random() ---> generates a random double value between 0.0 (inclusive) and 1.0 (exclusive)

Math.max(1, 2); // 2
int a = 3, b = 4, c = 5;

int min = Math.min(a, b);
min = Math.min(min, c);

min = Math.min(a, Math.min(b, c));

Math.PI
Math.E (exponential)

- Example#1: Quadratic.java
ax^2 + bx + c

We are going to read the value a, b, and c from the user and then apply the quadratic formula to 
derive the roots. 

delta = b*b - 4ac

root1 = -b + sqrt(delta) / (2a)
root2 = -b - sqrt(delta) / (2a)

x^2 + 2x + 1 = 0 => (x+1)^2 = 0 ===> roots are identical and both equal to -1

Double.isNaN(b) ---> true if b is NaN

- DecimalFormat (java.text): round the output values
format is non-static

1 ---> 1 + "" ---> "1"
"23.5" ---> 23.5

- Wrapper classes:
byte ---> Byte
short ---> Short
int ---> Integer
long ---> Long

float ---> Float
double ---> Double

char ---> Character
boolean ---> Boolean

All of them are part of java.lang
-------------------------------------------------------------------
			urgent

Delegate				Do It
Not Important					Important

					Schedule

Don't do it		Not urgent
--------------------------------------------------------------------

Example#2: 
Ask the user for a name. Then construct a new String consisting of 3 letter that are 
randomly selected from the input name. 

Example#3: 
Ask the user for two double values
Enter val1: 24.6
Enter val2: 23.5

Find the sum of the fractional parts and the average of the integer parts. 


















































 



 







