Nawa yadda variables da basic types ke aiki a Ruby?

Question

Accepted Answer

Ruby yana **dynamically typed** — variables ba sa bayyana nawa, kuma suna riƙe da kowane ƙima. Ruby yana da nau'uan iri-iri (duka abubuwa), kuma tana amfani da **naming conventions** (sigils) don nuna scope na variable.

## Variables da dynamic typing

```ruby
count = 42           # no type declaration — inferred
name = "Ann"
count = "now a string"   # dynamically typed — can change type
```

## Basic types (duka abubuwa ne)

```ruby
42              # Integer
3.14            # Float
"hello"         # String
:symbol         # Symbol (an immutable, interned identifier)
true / false    # Boolean (TrueClass / FalseClass)
nil             # NilClass — "nothing" (Ruby's null)
[1, 2, 3]       # Array
{ a: 1 }        # Hash (key-value)
1..10           # Range
```

## Variable naming conventions suna nuna scope

```ruby
name        = "local"      # local variable (lowercase)
@instance   = "instance"   # @ → INSTANCE variable (per object)
@@class_var = "class"      # @@ → CLASS variable (shared across instances)
$global     = "global"     # $ → global variable (avoid)
CONSTANT    = "constant"   # Uppercase start → CONSTANT (convention; can change with warning)
```

Ruby tana amfani da **sigils** (prefixes) don nuna scope na variable: sunan tsafi shine local, `@` don instance variables, `@@` don class variables, `$` don globals (ba a son), da uppercase don constants. Wannan yana bambanta — prefix din ya gaya maka scope a jiya.

## Truthiness (Ruby quirk)

```ruby
# in Ruby, ONLY false and nil are falsy — EVERYTHING else is truthy
puts "truthy" if 0        # prints — 0 is TRUTHY in Ruby! (unlike many languages)
puts "truthy" if ""        # prints — empty string is truthy too
puts "falsy" unless nil    # nil is falsy
```

**Kawai `false` da `nil` kawai ne falsy** a Ruby — `0`, `""`, da `[]` duka true ne (ba kamar yaruka ina 0/empty suke falsy). Abin mamaki na gida.

## Me yasa yake mahalaci

Ganewa game da Ruby variables da basic types shine ilmi na ainihi na kowane rana.

Ruby yana dynamically typed (variables suna riƙe da kowane ƙima, babu bayyana nawa), kuma fasalin da ya bambanta shi ne amfani da **naming conventions (sigils) don nuna scope na variable** — `@` don instance variables, `@@` don class variables, `$` don globals, uppercase don constants — saboda haka prefix na variable ya gaya maka scope kaafai, kuma wannan mahimmi ne ga karantawa da rubuta Ruby daidai (musamman `@instance` variables, da ake amfani da ita ne a cikin classes).
\