Merge pull request TheAlgorithms#1057 from EricFromCanada/gh-pages-updates

Add additional documentation

Author: adamhollett

_basics/operators.md

@@ -87,3 +87,28 @@ You can use multiple operators in a tag:
 ```
 
 `contains` can only search strings. You cannot use it to check for an object in an array of objects.
+
+## Order of operations
+
+In tags with more than one `and` or `or` operator, operators are checked in order *from right to left*. You cannot change the order of operations using parentheses — parentheses are invalid characters in Liquid and will prevent your tags from working.
+
+```liquid
+{% raw %}
+{% if true or false and false %}
+  This evaluates to true, since the 'and' condition is checked first.
+{% endif %}
+{% endraw %}
+```
+
+```liquid
+{% raw %}
+{% if true and false and false or true %}
+  This evaluates to false, since the tags are checked like this:
+
+  true and (false and (false or true))
+  true and (false and true)
+  true and false
+  false
+{% endif %}
+{% endraw %}
+```

_filters/first.md

@@ -36,3 +36,13 @@ Returns the first item of an array.
 
 {{ my_array.first }}
 ```
+
+You can use `first` with dot notation when you need to use the filter inside a tag.
+
+```liquid
+{% raw %}
+{% if my_array.first == "zebra" %}
+  Here comes a zebra!
+{% endif %}
+{% endraw %}
+```

_filters/last.md

@@ -36,3 +36,13 @@ Returns the last item of an array.
 
 {{ my_array.last }}
 ```
+
+You can use `last` with dot notation when you need to use the filter inside a tag.
+
+```liquid
+{% raw %}
+{% if my_array.last == "tiger" %}
+  There goes a tiger!
+{% endif %}
+{% endraw %}
+```

_filters/size.md

@@ -3,7 +3,7 @@ title: size
 description: Liquid filter that returns the number of characters in a string or the number of items in an array.
 ---
 
-Returns the number of characters in a string or the number of items in an array. `size` can also be used with dot notation (for example, `{% raw %}{{ my_string.size }}{% endraw %}`). This allows you to use `size` inside  tags such as conditionals.
+Returns the number of characters in a string or the number of items in an array.
 
 <p class="code-label">Input</p>
 ```liquid
@@ -33,7 +33,7 @@ Returns the number of characters in a string or the number of items in an array.
 {{ my_array | size }}
 ```
 
-Using dot notation:
+You can use `size` with dot notation when you need to use the filter inside a tag.
 
 ```liquid
 {% raw %}

_filters/sort.md

@@ -3,7 +3,7 @@ title: sort
 description: Liquid filter that sorts an array in case-sensitive order.
 ---
 
-Sorts items in an array by a property of an item in the array. The order of the sorted array is case-sensitive.
+Sorts items in an array in case-sensitive order.
 
 <p class="code-label">Input</p>
 ```liquid
@@ -20,3 +20,14 @@ Sorts items in an array by a property of an item in the array. The order of the
 
 {{ my_array | sort | join: ", " }}
 ```
+
+An optional parameter specifies which property of the array's items to use for sorting.
+
+```liquid
+{% raw %}
+{% assign products_by_price = collection.products | sort: "price" %}
+{% for product in products_by_price %}
+  <h4>{{ product.title }}</h4>
+{% endfor %}
+{% endraw %}
+```

_filters/sort_natural.md

@@ -3,7 +3,7 @@ title: sort_natural
 description: Liquid filter that sorts an array in case-insensitive order.
 ---
 
-Sorts items in an array by a property of an item in the array.
+Sorts items in an array in case-insensitive order.
 
 <p class="code-label">Input</p>
 ```liquid
@@ -16,5 +16,18 @@ Sorts items in an array by a property of an item in the array.
 
 <p class="code-label">Output</p>
 ```text
-giraffe, octopus, Sally Snake, zebra
+{% assign my_array = "zebra, octopus, giraffe, Sally Snake" | split: ", " %}
+
+{{ my_array | sort_natural | join: ", " }}
+```
+
+An optional parameter specifies which property of the array's items to use for sorting.
+
+```liquid
+{% raw %}
+{% assign products_by_company = collection.products | sort_natural: "company" %}
+{% for product in products_by_company %}
+  <h4>{{ product.title }}</h4>
+{% endfor %}
+{% endraw %}
 ```

_tags/iteration.md

@@ -23,6 +23,26 @@ Repeatedly executes a block of code. For a full list of attributes available wit
 hat shirt pants
 ```
 
+### else
+
+Specifies a fallback case for a `for` loop which will run if the loop has zero length.
+
+<p class="code-label">Input</p>
+```liquid
+{% raw %}
+{% for product in collection.products %}
+  {{ product.title }}
+{% else %}
+  The collection is empty.
+{% endfor %}
+{% endraw %}
+```
+
+<p class="code-label">Output</p>
+```text
+The collection is empty.
+```
+
 ### break
 
 Causes the loop to stop iterating when it encounters the `break` tag.