added basic info about type safety and optionals (#27860)

* added basic info about type safety and optionals

* add link for optionals, renamed links and title  

also renamed the directory folder

* added basic info about type safety and optionals

added optionals link and renamed links and directory

* added basic info about type safety and optionals

added optionals link and renamed links and directory

* added basic info about type safety and optionals

also added "swift optionals" link and renamed original link to "type safety and type inference" and also renamed directory

* added basic info about optionals

added link to swift optionals and change the name of the first link and the directory

* added info on swift optionals

renamed links and directory folder

* added info about type safety and optionals

added a link to swift optionals and change folder name and a link's name to type safety and inference

* added info about optionals

added a link to optionals docs, change link and folder name to "type safety and inference", similarly with the title tag

* Update index.md

* Update index.md

* added info on swift optionals and type safety

altered link and directory names and added a link to optionals docs

* added info for swift type-safety and optionals

changed link and directory name to type safe and inference
added link to swift optionals doc

* Update guide/english/swift/type-safety-and-inference/index.md

Co-Authored-By: Tom <20648924+moT01@users.noreply.github.com>

* Update guide/english/swift/type-safety-and-inference/index.md

Co-Authored-By: Tom <20648924+moT01@users.noreply.github.com>

* Update guide/english/swift/type-safety-and-inference/index.md

Co-Authored-By: Tom <20648924+moT01@users.noreply.github.com>

* Update guide/english/swift/type-safety-and-inference/index.md

Co-Authored-By: Tom <20648924+moT01@users.noreply.github.com>

* Update guide/english/swift/type-safety-and-inference/index.md

Co-Authored-By: Tom <20648924+moT01@users.noreply.github.com>

* Update guide/english/swift/type-safety-and-inference/index.md

Co-Authored-By: Tom <20648924+moT01@users.noreply.github.com>

* Update guide/english/swift/type-safety-and-inference/index.md

Co-Authored-By: Tom <20648924+moT01@users.noreply.github.com>

* changed the directory name to match the title

* modified folder name to have the proper format :-)

guide/english/swift/type-inference/index.md

@@ -1,25 +0,0 @@
----
-title: Type Inference
----
-## Type Inference
-
-Swift uses type inference. So if you write some code like the code in the example below it’s pretty obvious what each type is.
-
-#### Example:
-```swift
-    let iPhone: String = “iPhone”
-    let yearIntroduced: Int = 2007
-    let isAwesome: Bool = true
-```
-
-So we can clean up the code to look like the example below, and Swift can infer the type for use.
-
-#### Example:
-```swift
-    let iPhone = “iPhone”       // Inferred as String
-    let yearIntroduced = 2007   // Inferred as Int
-    let isAwesome = true        // Inferred as Bool
-```
-
-#### More Information:
-- <a href='https://docs.swift.org/swift-book/LanguageGuide/TheBasics.html#ID322' target='_blank' rel='nofollow'>The Swift Programming Language</a>

guide/english/swift/type-safety-inference-and-optionals/index.md

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+---
+title: Type Safety, Inference, and Optionals
+---
+## Type Inference
+
+Swift uses type inference. So if you write some code like the code in the example below it’s pretty obvious what each type is.
+
+#### Example:
+
+```swift
+    let iPhone: String = “iPhone”
+    let yearIntroduced: Int = 2007
+    let isAwesome: Bool = true
+```
+
+So we can clean up the code to look like the example below, and Swift can infer the type for use.
+
+#### Example:
+
+```swift
+    let iPhone = “iPhone”       // Inferred as String
+    let yearIntroduced = 2007   // Inferred as Int
+    let isAwesome = true        // Inferred as Bool
+```
+
+## Type Safety
+
+Swift is a "type-safe" language. This means that by design the language helps programmers be more clear about the types they are using and helps mitigate and/or prevent common type errors - like trying to pass a string where it requires an integer. One core mechanism of this type-safe design are Optional Types.
+
+## Optional Types
+
+When a variable's type is an optional type it denotes that its value can have a value **_or_** no value at all (nil). 
+
+You declare an optional by appending a question mark at the end of the type declaration.
+ 
+```swift
+    var optionalFloat: Float?          // This is an Optional Float
+    var optionalString: String?  = "an optional string"   // and an Optional String
+ 
+    let normalFloat: Float = 0.5    // This is an ordinary Float
+    var normalString = "a string"   // and a String
+``` 
+
+**Note:** since optionalFloat is not assigned a value it is given a default value of nil
+
+### Unwrapping Optionals
+
+Optionals are considered a different type then its non-optional variant. For example in the above code "optionalFloat" and "normalFloat" are _not_ the same type. When you try to access an optional variable like you would a normal variable the value would be of Optional(_SomeValue_).
+
+```swift
+    var optionalInt: Int? = 5
+    let normalInt = 10
+    print(optionalInt) // Optional(5)
+```
+
+If you try to utilize the optional variable like normal you will get an error.
+```swift
+    let sumError = normalInt + optionalInt //error!
+```
+
+Instead you must first "unwrap" the optional before you can utilize the data. There are a couple of ways doing so: forced unwrapping it and optional binding.
+
+#### Forced Unwrapping
+
+If you are **certain** that an optional does contain a value, you can force-unwrap it by appending an exlamation mark at the end of it.
+
+```swift
+    if(optionalInt != nil) { // make sure the optionalInt has a value, otherwise will get a runtime error
+        let sum = normalInt + optionalInt! // <-- forced unwrapped
+    }
+```
+
+#### Optional Binding
+
+Optional Binding is a special kind of condition statement (either with an if or a while) at which it automatically unwraps an optional if it has a value, and then stores that value in the designated variable. That variable can then be utilized within the if/while statements body normally.
+
+```swift
+    if let unwrappedInt = optionalInt {
+        let sum = normalInt + unwrappedInt; // 15
+    }
+ ```
+
+If the optional does not have a value (nil), then the condition would be considered false and its code would not execute and the program will continue on normally. 
+
+
+#### More Information:
+- [Type-Safety and Type Inference](https://docs.swift.org/swift-book/LanguageGuide/TheBasics.html#ID322)
+
+- [Swift Optionals](https://docs.swift.org/swift-book/LanguageGuide/TheBasics.html#ID330)