Beginner PHP Tutorial - 18 - if / if else Statement Video Lecture | PHP for Absolute Beginners: From Novice to PHP Master - Web Development

hello this is Alex from PHP academy' de
org and in this video for the new Boston
we are going to be looking at if
statements within PHP now an if
statement is a statement that lets us to
compare or not compare or evaluate and
something whether it's true or false and
act on that for example in real-life
situations you would say if I did this
there would be an outcome or otherwise
if I didn't do this there would be
another outcome and we can demonstrate
this I'm going to show you the syntax
first of all and this is just simply if
and then we have two brackets where our
statement to be evaluated goes inside
here here and then we start a curly
bracket we come down a few lines and we
end a curly bracket then what we do is
we basically come in and Pat our
statement in here so for now I'm going
to say if one now true so the way this
reads is if one echo true now one by
itself is a statement within programming
in general that will evaluate to true
it's a it's there it's one equals one
it's one is no other there's no
comparison it just equals true otherwise
we equal or we echo sorry folks
okay so we're basically saying if one on
its own if this is true we execute this
block here this is called a block
otherwise by using the else keyword
execute this block here what's
highlighted in blue at the moment is a
block so this is how we write it out you
might see it sometimes written like this
this is a lot of an easier way to read
it and if you're new to programming it
doesn't matter how you write it
but generally I write like this so this
block here will be executed if one is
true which it is and it always is and
otherwise this block here will be
executed so let's just run this in our
browser and see what happens
we have been displayed with the text
true because this is true now what about
if 0 now you can probably guess that 0
is an automatic false one is true and 0
is false so in this instance putting a 0
in we're evaluating 0 is 0 true or false
it's false so we should be displayed
with the text false the same as if we
were to write true this would equal true
and if we were to type in false this is
equal to false now this is pretty boring
we want to start making some comparisons
inside so I'm just going to use an
example of one of the comparison
operators which is double equals and
this means is equal to and it looks like
this and either side of it you're going
to do your values to compare so I want
to say does 1 equal 1
now this reads as does 1 or is 1 equal
to 1 and because 1 is equal to 1 we're
going to be executing this block if one
wasn't equal to 1 we'd be executing this
block so let's just run that and that's
true now I'm going to change this to
does 1 it is 1 equal to 2 and obviously
that is false so you can see how this
block here this is called an if
else statement because we're using the
keywords if and we're using the keywords
else you can have an if statement just
on its own if if it doesn't happen to
equal true we just in this case not
going to output anything because there's
no else to tell us what to do otherwise
so now let's just return back to that
now what we can do is we can start
saying things like if and we can have a
variable up here that's what it will say
text equals let's say something
so if text equals something echo true in
this case we will be echoing out true to
the screen because it is true otherwise
echo false so now what I can do is
change this to let's say something else
it doesn't equal that so we're going to
be displayed with false so that is the
basic structure and the use of an if
statement we have this is basically
called an if-else statement so we've got
if-else and depending on whether this
statement here is evaluated to true or
false we echo out the corresponding
block