Today I Learnt 11

Python List Operations

If we start with a list

seq = [1,2,3,4]

then we have the following operations:

Go 101

This is a continuation of my notes on learning Go.

Keywords

• From Go 101
• Go has precisely 25 keywords:

  break     default      func    interface  select
  case      defer        go      map        struct
  chan      else         goto    package    switch
  const     fallthrough  if      range      type
  continue  for          import  return     var
  

Identifiers

• Composed of Unicode letters, Unicode digits and _ (underscore)

• Starts with a Unicode letter or _. (Not a number!)

• Identifier _ is a special identifier, it is called blank identifier.

• All names of types, variables, constants, labels, package names and package import names are identifiers.

  Exported identifier	Non-exported/unexported identifier
  Starts with upper case letter	Does not start with upper case letter
  Kinda like public	Kinda like private
  Shared between files in a package	Local to usually a function or file
  Eg: Player_9, DoSomething, VERSION, Ĝo, Π	_, _status, memStat, book, π, 一个类型, 변수

• Some items that cannot be used as identifiers:

  Reason	Examples
  Starting with a Unicode digit:	1234, 2clear
  Containing disallowed Unicode character	a.b, *prime, $name, email@domain.com
  Keywords	type, range

Built-in Types

• There are two built-in type aliases:
  1. byte: is an alias of uin8.
  2. rune: is an alias of int32.
• The integer types whose names starting with a u are unsigned types.
• The number in the name of a type means how many binary bits a value of the type will occupy in memory at run time.
• The size of int and uint values are 4 on 32-bit architectures, and 8 on 64-bit architectures.
• The size of uintptr value must be large enough to store the uninterpreted bits of any memory address. (I don’t understand this statement. How large can a memory address be?)
• The real and imaginary parts of a complex64 value are both float32 values, and the real and imaginary parts of a complex128 value are both float64 values.
• Zero value: Each built-in type has a zero/default value.

  Category of Type	Zero Value
  Boolean type	false
  Numeric types	0 (might have different size in memory)
  String type	Empty string