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An if statement evaluates a variable and executes a block of code if the value is true.
{% if greeting == 1 %}Formula
< h1 > Hello </h1 >{% endif %}The elif keyword says "if the previous conditions were not true, then try this condition".{% if greeting == 1 %}Formula
< h1 > Hello </h1 >{% elif greeting == 2 %}Formula
< h1 > Welcome </h1 >{% endif %}The else keyword catches anything which isn't caught by the preceding conditions.{% if greeting == 1 %}Formula
< h1 > Hello </h1 >{% elif greeting == 2 %}Formula
< h1 > Welcome </h1 >{% else %}Formula
< h1 > Goodbye </h1 >{% endif %}== operator, which is used to check if a variable is equal to a value, but there are many other operators you can use, or you can even drop the operator if you just want to check if a variable is not empty:
{% if greeting %}Formula
< h1 > Hello </h1 >{% endif %}
==Is equal to.
{% if greeting == 2 %}Formula
< h1 > Hello </h1 >{% endif %}
!=Is not equal to.
{% if greeting != 1 %}Formula
< h1 > Hello </h1 >{% endif %}< Is less than.
{% if greeting < 3 %}Formula
< h1 > Hello </h1 >{% endif %}
<=Is less than, or equal to.
{% if greeting <= 3 %}Formula
< h1 > Hello </h1 >{% endif %}> Is greater than.
{% if greeting > 1 %}Formula
< h1 > Hello </h1 >{% endif %}
>=Is greater than, or equal to.
{% if greeting >= 1 %}Formula
< h1 > Hello </h1 >{% endif %}and To check if more than one condition is true.
{% if greeting == 1 and day == "Friday" %}Formula
< h1 > Hello Weekend!</h1 >{% endif %}or To check if one of the conditions is true.
{% if greeting == 1 or greeting == 5 %}Formula
< h1 > Hello </h1 >{% endif %}Formula
and/orCombine and and or.
{% if greeting == 1 and day == "Friday" or greeting == 5 %}Parentheses are not allowed in if statements in Django, so when you combine and and or operators, it is important to know that parentheses are added for and but not for or. Meaning that the above example is read by the interpreter like this:
{% if (greeting == 1 and day == "Friday") or greeting == 5 %}in To check if a certain item is present in an object.
{% if 'Banana' in fruits %}Formula
< h1 > Hello </h1 >{% else %}Formula
< h1 > Goodbye </h1 >{% endif %}not in To check if a certain item is not present in an object.
{% if 'Banana' not in fruits %}Formula
< h1 > Hello </h1 >{% else %}Formula
< h1 > Goodbye </h1 >{% endif %}is Check if two objects are the same.
== operator, because the == operator checks the values of two objects, but the is operator checks the identity of two objects. In the view we have two objects, x and y, with the same values:
Example views.py
from django.http import HttpResponse from django.template import loader
def testing(request):Formula
template = loader.get_template('template.html')context = {
'x': ['Apple', 'Banana', 'Cherry'],
'y': ['Apple', 'Banana', 'Cherry'],
}
return HttpResponse(template.render(context, request))The two objects have the same value, but is it the same object?
{% if x is y %}Formula
< h1 > YES </h1 >{% else %}Formula
< h1 > NO </h1 >{% endif %}Let us try the same example with the == operator instead:
{% if x == y %}Formula
< h1 > YES </h1 >{% else %}Formula
< h1 > NO </h1 >{% endif %}How can two objects be the same? Well, if you have two objects that points to the same object, then the is operator evaluates to true:
{% with %}tag, which allows us to create variables in the template: