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chapters: 2.1 to 2.2.3 (how to declare (can have it eq a val - called…

- - - - byte
        
        range –128 . . . 127 - 1 byte size
      - long
        
        19 decimal digits - 8 byte size
      - short
        
        range –32,768 . . . 32,767 - 2 byte size
  - - - half the storage as a double - only stores 7 decimal digits
      - rarely used
- - - - this is very diff from a var declaration. Var declaration ex: int x = 6; Var Assignment ex: x = 8;
      - = does NOT mean equal to
      - new ex: totalVolume = totalVolume + 2; means to look up the value stored in the variable totalVolume, add 2 to it, and place the result back into totalVolume
  - - - use big number objects. Big number objects are objects of the BigInteger and BigDecimal classes in the java.math package.
        
        essentially no limits on their size and precision. However, computations with big number objects are much slower than those that involve number types. Perhaps more importantly, you can’t use the familiar arithmetic operators such as (+ - *) with them. Instead, you have to use methods called add, subtract, and multiply
        
        ex: BigInteger oneHundred = new BigInteger("100"); BigInteger fiftyMillion = new BigInteger("50000000"); System.out.println(oneHundred.multiply(fiftyMillion)); // Prints 5000000000
- - - - cannot hold a val a little more than 2 billion
        
        going over the limit results in overflow error - this means any number computed using the int var will not be accurate bc it cannot hold the large value that is assigned to it
    - - round off error: numbers are represented in the binary number system, using only digits 0 and 1. As with decimal numbers, you can get roundoff errors when binary digits are lost. So this is where precision is lost
        
        You can deal with roundoff errors by rounding to the nearest integer (see Section 2.2.5) or by displaying a fixed number of digits after the decimal separator (see Section 2.3.2).
- - - - application: Suppose you have an amount of pennies in a piggybank: int pennies = 1729; You want to determine the value in dollars and cents. You obtain the dollars through an integer division by 100: int dollars = pennies / 100; // Sets dollars to 17 The integer division discards the remainder. To obtain the remainder, use the % operator: int cents = pennies % 100; // Sets cents to 29
        
        n % 10 is always the last digit of n & n % 100 is last 2 digits of n