Java Review Note 1

• Java
• Note

Mar 19, 2018

primitive type

• number
  • int : 4 byte
  • short : 2 byte
  • long : 8 byte
  • byte: 1 byte -127 ~ 127
  • no unsigned type in java
• float
  • float 4 byte
  • double 8 byte
  • float operation follow IEEE 754
    • Double.POSITIVE_INFINITY
    • Double.NEGATIVE_INFINITY
    • Double.NaN
• char: unicode

• boolean

• final vs const (c/c++/c#)

• type converting

• string
  • immutable
  • String vs StringBuilder vs StringBuffer
  • in - new Scanner(System.in) vs Console which can only read one line
    • password visible vs array
• BigInteger and BigDecimal
  • valueOf
    • BigInteger test = BigInteger.valueOf(100);
  • can not use operation such as * /
    • Java not support operation override
    • need to use add or multiply

Package and import

• package vs path