Beginner PHP Tutorial - 49 - String Functions: String Position Part 2 Video Lecture | PHP for Absolute Beginners: From Novice to PHP Master - Web Development

now what happens inside our while loop
so while our string position equals STR
pause if nothing is found in the STR
pause it will return a 0 so remember 0
inside here will mean a false therefore
the loop will be broken but for now as
long as the string position is found we
want to echo out the string position so
we just simply do echo string position
and I'm just going to append a break on
to that let's just make this a bit more
user-friendly we could say echo echo
found at we can even include the word so
let's say find found at ok so what this
is going to do is for every every for
every time it's found we're going to
echo the position and obviously the word
we're going to iterate way and then
we're going to put a line break on the
end but now what we want to do is we
want to create a new offset because at
the moment we're going to find the we're
going to find the string that's that's
absolutely fine we're going to echo out
the first instance of the string found
within here so it will be at position 2
however then all we're going to be doing
is searching from the start again so
we're going to be searching from
position 0 again so we're going to be
searching and we're going to find the
same string so you'll find that if you
do run your page at this point then your
page will probably crash it might crash
your browser because what we actually
have here is now an endless loop so now
what we need to do is we need to create
the offset value and I'm going to say
offset is equal to string position so
this is the current position found let's
just run through so if we were to find
it at position 2 we then need to add 2
on Twitter to begin the search from here
so string position add 2 now why is this
not good well I've already explained
we've got the length of the string to
find here so that's the amount of
characters just to skip so all I need to
do is add on this variable
length now we can run and test our
program now to see if everything is
working so let's just refresh and you
can now see Oh
oh yeah okay so I'm reading this as is
found out but obviously our word is is
so let's just make this bold so it
doesn't look as confusing confuse me for
a minute there okay so okay so we've got
is found at two so we found it a
position to let's just double check that
so we've got one two and then we've
found it then what we've done is here
within the office Cape we've skipped two
so we've started from this position here
and the offset has been read in here so
the offset has now been read out on to
its found it - so the offsets now
starting at position 4 and now we go one
more and we find it at position 5 which
is here we skip to and we start at
position 7 and then we find it all the
way up here at position 25 then we skip
another two and it can't be found any
more therefore this while loop will be
evaluated to false because this value of
string position will equal zero so now
we've successfully found everything now
I know we've used a lot of variables
like the find in here and the fine
lengths in here and the reason for this
is now if I wanted to search for a
completely different word inside here
for example if I wanted to change this
to string everything is now going to be
updated so the fine length is going to
be updated which is going to be put in
here so now instead of skipping two
characters we're skipping one two three
four five six and we're also updating
this inside our function so we've only
had to change one value now why is this
going to be useful let's just test it
out first and we'll see if it works
string found at 10 so let's just check
this one two three four five six seven
eight nine ten yeah it's found that so
why is this useful well let's say we had
a form down here and we wanted to ask
the user to input a certain value we
could pass this find variable as say
dollar underscore post Abdulla
underscore get to find for example so we
could specify or we could allow the user
to specify a string
I wanted to find in another particular
string and therefore our program that
we've just created here would
automatically update for whatever string
was entered so that's basically how the
string position function works and how
useful it can actually be