# print variable 
I am {{ hamburgers }}

# print hashed variable 
{{ content.body['#view_mode'] }}

# string together
{{ 'I am ' ~ var.something }}

# set a variable
{% set var = content.string %}

# set array
{% set myarray = {'acorn': 'awesome', 'fudge': 'better'} %}

# foreach loop for myarray
{% for arrayfor in myarray %} {% endfor %}

# or
{% if (a or b) %} {% endif %} 

# and
{% if (a and b) %} {% endif %} 

# if conditional
{% if myarray %} {% endif %}

# not empty 
{% if myarray is not empty %} {% endif %}

# isset 
{% if myarray is defined %} {% endif %}

# !isset
{% if myarray is not defined %} {% endif %}

# greater than 
{% if myarray.length > 0 %} {% endif %} 

# starts with 
{% if 'Fudge' starts with 'F' %} {% endif %}

# ends with 
{% if 'Funky' ends with 'y' %} {% endif %}

# contained within  
{{ 1 in [1, 2, 3] }}
{{ 'cd' in 'abcde' }}

# ternary 
{{ funky ? 'yes' : 'no' }} 

# regex 
{% if numbers matches '/^[\\d\\.]+$/' %} {% endif %}

# strip_tags
{{ myarray.acorn|striptags }} 

# translate 
{{ 'Hello, World|t }} 
{{ 'Hello @acorn'|t({ '@acorn': myarray.acorn }) }}

# Renderable arrays can be printed by default 
{% set numbers = [{'#markup': 'One'}, {'#markup':'Two'}, {'#other':'Three'}] %}
{{ numbers }} // prints 'OneTwo' 

# safe join 
{{ [1, 2, 3]|safe_join('|') }} is 1|2|3

# escape 
{{ user.username|escape }}

# filter proper class
<div class="icon-{{ item.title|clean_class }}" >

# filter proper id
<div id="icon-{{ item.title|clean_id }}" >

# title
{{ 'the apple is green'|title }}

# capitalize
{{ 'how are you'|capitalize }}

# lowercase
{{ 'HOWDY'|lower }}

# uppercase
{{ 'howdy'|upper }}

# without 
{{ content|without('links') }} // removes content.links

# date 
{% if date(user.created_at) < date() %} {% endif %} 

# default 
{{ var|default('var is not defined') }}

# length  
{% if users|length > 10 %} {% endif %}

# trim: whitespace or chars  
{{ '  I like Twig.'|trim('.') }}

# merge: add to array 
{% set values = values|merge(['cat', 'dog']) %} 

# nl2br converts to <br>
{{ "Let us have apples\nIt will be great"|nl2br }} 

# formatting numbers
{{ 9800.333|number_format(2, '.', ',') }}

# reverse
{{ '1234'|reverse }}

# round
{{ 23.535|round(1, 'floor') }}

# slice
{{ '12345'|slice(1, 2) }}  // 23

# sort an array 
{% users|sort %}

# using kint in twig file 
{{ kint(page.content) }}

# print variable
{{ dump(var) }}

# print all variables
{{ dump(_context) }}

# print only keys 
{{ dump(_context|keys) }}

# print formatted keys or value 
{% for key, value in _context %}
  <li>{{ key }}</li>
{% endfor %}

# chaining filters
{{ 'how are you'|capitalize|clean_class }}

# add new class to attributes array 
{% set classes = ['region-' ~ region|clean_class] %}
<div{{ attributes.addclass(classes) }}>