From 0ddbda2c78769b9e2cdea8be1d2ba2286c55e0b4 Mon Sep 17 00:00:00 2001
From: Anna Tyrrell <16312226+githesp@users.noreply.github.com>
Date: Fri, 15 Feb 2019 05:09:20 +1300
Subject: [PATCH] Add updating and destructuring examples. (#27628)

---
 guide/english/typescript/tuple-type/index.md | 61 +++++++++++++-------
 1 file changed, 41 insertions(+), 20 deletions(-)

diff --git a/guide/english/typescript/tuple-type/index.md b/guide/english/typescript/tuple-type/index.md
index 5156c0b0d7..6911a3c259 100644
--- a/guide/english/typescript/tuple-type/index.md
+++ b/guide/english/typescript/tuple-type/index.md
@@ -4,7 +4,7 @@ title: Tuple Type
 
 # Tuple Type
 
-Express an array in which a fixed number of elements of types is known, but not the same.
+Expresses an array with a fixed number of elements of known (but possibly different) types. For example:
 
 ```typescript
 let arr: [string, number];
@@ -12,54 +12,75 @@ let arr: [string, number];
 // This is correct
 arr = ['Hello', 7];
 
-//This is incorrect
+// This is incorrect
 arr = [7, 'Hello'];
 ```
 
 When accessing an element outside the known indices, it will use a union type:
 
 ```typescript
-arr[3] = 'World!'
+arr[3] = 'World!';
 // OK, 'string' can be assigned to 'string | number'
 
-// Error, 'boolean' is not a 'string | number'
 arr[5] = false;
 // Error, 'boolean' is not a 'string | number'
 ```
 
 ## Properties
-In Typescript's type you can have some buit-in properties. Forexample length or some other unique each types.
+Tuples have some built-in properties, such as length.
 
 ### length
-This property said, how many element has it's element.
+The number of elements:
 
 ```typescript
-let tuple = []; //you can initialize it after the declaration too, not just the method above
-tuple[0] = 10;
-tuple[1] = 'Mike';
+let tuple = [10, 'Mike']; 
 let number = tuple.length;
-//number = 2;
+// number = 2
 ```
 
 ## Built-in methods
-In Typescript's type you can use some built-in functions. Each type has common and unique methods.
-Below you can read about the most used ones of the tuple type's methods.
+Tuples have some built-in functions, such as adding a new element and removing an element:
 
 ### pop()
-Removes the last element from a tuple.
+Removes the last element from a tuple and returns that element.
 ```typescript
-var tuple = [10,'Emma',11,'Lily',12,'Mike Ross'];
-tuple.pop();
-//tuple = [10,'Emma',11,'Lily',12,]
-//We popped 'Mike Ross' from the tuple
+let tuple = [10,'Emma',11,'Lily',12,'Mike Ross'];
+let popped = tuple.pop();
+// tuple = [10,'Emma',11,'Lily', 12]
+// popped = 'Mike Ross'
 ```
 
 ### push()
-Adds element to the end of the tuple.
+Adds an element to the end of the tuple.
 ```typescript
-var tuple = [10,'Emma',11,'Lily',12,'Mike Ross'];
+let tuple = [10,'Emma',11,'Lily',12,'Mike Ross'];
 tuple.push('Rachel Zane');
-//tuple = [10,'Emma',11,'Lily',12,'Mike Ross','Rachel Zane']
+// tuple = [10,'Emma',11,'Lily',12,'Mike Ross','Rachel Zane']
+```
+
+## Destructuring
+The following is an easy way to break apart a tuple in TypeScript:
+```typescript
+let tuple = ['sheep', 4]; 
+[a, b] = tuple;
+// a = 'sheep'
+// b = 4
+```
+
+## Updating
+You can initialize the tuple after the declaration:
+```typescript
+let tuple = []; 
+tuple[0] = 'cow';
+tuple[1] = 'Mike';
+// tuple = ['cow', 'Mike']
+```
+
+You can update an existing tuple in the same way you update an array:
+```typescript
+let tuple = ['sheep', 4]; 
+tuple[0] = 'cow';
+// tuple = ['cow', 4]
 ```
 
 [More info about tuples on TutorialsPoint](https://www.tutorialspoint.com/typescript/typescript_tuples.htm)