Beginner PHP Tutorial - 80 - The explode Function with File Handling Example Video Lecture | PHP for Absolute Beginners: From Novice to PHP Master - Web Development

hi this is Alex from PHP academy' org
and this is a tutorial for the New
Boston now in this tutorial we're going
to be learning to read data from a file
but obviously when you're reading data
from a file it's not always on a line by
line basis you might find that you've
got commas separating your values and in
this case we've got a few names here
with commas separating each value now
how do we deal with reading this in now
we've already seen examples of reading
in file data but for now what we want to
do is we want to create a handle as
we've done previously I've got this
names.txt up here but I'm just going to
close it so it doesn't interfere with
our program I don't change anything
inside so handle equals F open and we
want to pick a file to open which is
names.txt and we're going to eat we're
going to open this for reading so we're
going to use an R here okay now what
we're going to do is we need to create a
way to read the contents of the file
echo the contents of the file and that
that's the first stage I'm going to take
just echoing out the contents to the PHP
page at the moment the it looks like
this nothing's really happening
so how do we do this what we do is we we
echo F read and we take the handle in
there now the second argument in this is
the amount of data we want to read in
for now I'm just going to type a
thousand just to make sure we read in
all the characters however well let's
refresh first and you can see we've
taken in all the data from the names txt
far from Alex to sandra we've taken in
all the data and we're displaying it now
I don't want to read in a thousand bits
or but I think it's byte so much I'm not
too great with that but this is the
amount of data it's reading in could be
characters I'm not sure but something to
look up
so I want to take in the file size
rather than keep specifying you know if
I was reading in a massive long file I
might say Oh we'll just read in that
amount of characters
you're wasting you're wasting it doesn't
look neat either so what I want to do is
I want to use a function called file
size and then handle so basically all
this is doing is taking the file size
and reading in the file as a whole not
any more not any less so let's see if
that's worked oh right okay so okay
basically what we've done is um as
opposed to reading in the you know a
particular file we're reading in this
open file so what we need to do up here
is we need to specify the file name so
I'm going to specify the file name as
names.txt that means that down here I
can replace this with file name and then
I can replace this with file name as
well so now let's refresh and we should
have that that file up ok so just to
show you an example if I wanted to only
read in say five we just get the first
five characters of that so always use
this file size and it will just open the
exact amount of data within your file
okay so and we don't want to echo this
out but what we do want to do is put it
in a variable so I'm going to call this
variable data in now what we want to do
with this is we want to split it up and
our the character we want to split from
is commas so let's refresh again all
right
echo that out and refresh now we want to
split it up through commas and we use a
function here called explode so I'm
going to say names
array equals explode what we do is we
use we tell PHP the character we want to
explode it with and then we read in the
photo reading the what we want to
explode so if for example in here we had
Alex Billy Dale okay and we wanted to
explode that we just be left with an
array with Alex Billy and Dale but
because we've got this data in variable
with our data all data in I mean that's
what we want to read in we want to read
in this and we want Alex inner in an
array element Billy
Peter Dale so if we refresh nothing's
happened no errors have occurred which
is fine now to test this we can use the
for each and we can say for each names
array as name and what once there is
echo name and then we just append a
break on to that so essentially what
we're doing is we're converting this
file from a comma comma delimited file
to a line by line echoing out to our
browser and displaying the data to our
browser so if we refresh hopefully that
should work okay so you can see that
they're now on a line by line basis now
there's one thing that you need to
notice when dealing with these files is
that they do actually have extra extra
spaces on I believe so let's just add a
dot in there to test that another day
okay that's absolutely fine that's work
well
okay so we've now got this data that's
been read in on a common line for us
we've used explode and we've read this
in as an array so now what we can do is
we can do anything we like this data
because it's invalid it's in an element
of an array for example let's just get
rid of this if I wanted to say
names array and so the say the first
element of the array so the array with
the key of 0 the key 0 has the value
Alex because it's the first name in the
list so we just reduce we're just
reducing that down and printing out Alex
or echoing out Alex so you can do
anything you like with this data now
that is in an array and we've done that
simply by the explode function using a
commerce say oh yeah it's separated by
comma and if it was separated by spaces
you could just use a space in here and
then just reading in the data just here
so that's how simple it is to read in
sort of comma separated values within a
file