Beginner PHP Tutorial - 78 - File Handling: Reading a File Video Lecture | PHP for Absolute Beginners: From Novice to PHP Master - Web Development

hello again this is Alex from PHP
academy' dog producing this video for
the New Boston now in the last file
handling example we looked at a pending
data and we created this form here which
appended data to the end of this file
here and so far we've appended four
names now what happens if we want to
read in this data I want to read in each
name and display them to the user and
what we're going to do is we're going to
create this inside this process here so
when they submit a new name it just
reproduces a list of the current names
and I don't want to reproduce a list of
it line on a line by line basis I want
to produce it separated by commas now
you may look at this file and think how
are we going to do this because they're
not separated by commas they're on a
line by line basis well we have various
functions that allow us to open files
and read in on a line by line basis now
remember using the for each statement we
can use that again here so what I'm
going to do is underneath here I'm going
to create a little section for myself to
read this file in in fact we can do it
under the F close it probably be a lot
better so let's create a variable could
read in and this is going to be using
the file function this time we're not
using F open we're just using file and
what we can do is we can specify a file
here and we're going to specify the file
type of R so we're reading that data in
so that is obviously going to be
names.txt so let's just add another name
to the list and just double check if
this works properly and so Sandra click
Submit
expects parameter two to be long oh okay
okay so let's get rid of that so we're
basically just reading this in we're
using the file function to read this and
there's no need to use this because
we're reading an underlined by line
basis we're using this file function
rather than F open so for now just stick
to this file function and we're going to
read it in that way so let's refresh
that actually that that will have
written so let's just check back on that
okay yes we've got signed rather to the
end of the list so our goal is to read
it read the file in which we've done now
what we want to do is use for each okay
and we want to say read in as name okay
so or or or f9 we'll call it because
it's the name within the file so now
what we can do with standard notation
with the forage we can echo out this F
name each time and then what we can do
is we can append a comma onto the end of
it so the process goes we a start a
variable called read in we use the file
function to read in this names txt file
what this will do this function will do
is it will read in the line reading the
file sorry on a line by line basis there
are other ways to do this but they're a
bit more complicated however this is the
easiest way possible now what we're
doing is we're using a for each
statement and we're using the array
that's been read in and we're using this
array each element of this array as F
name then we're echoing our f name with
the comma so above this we could write
current names in file and then that
should echo them out now you'll probably
notice that when we run the script we're
going to have an extra comma after the
list so let's just try and add another
name to this and see what happens so I'm
going to take down and I'm going to
click Submit now you'll see it says
current names in file
Alex comma Billy commerce Stephen at the
moment it's not looking to gray so let's
just tidy that up we need to first of
all see what's going on here now
alex has a space oft where as does Billy
as does every other name in the list and
we can use a function called trim to
trim this down and this removes
whitespace from the start and the end of
our name as well as any other special
characters so just by adding this
function around the name as we echo here
we can see that it's actually if we add
another name in let's say Josh submit
you can see that it's removed that white
space now what we can do is we can just
get rid of or add a space in after that
we'll add another name in let's say Dale
okay so now you can see that it's
displaying properly now what we need to
do is we need to analyze this problem
we've got with a comma at the end here
so as well as reading a file in in this
tutorial we want to actually read it
improperly and display things properly
so we need a way of counting all the
elements in this in this text file and
we can do that with the count function
so I'm going to create a new variable
here called read in count and that's
going to equal count a function count
and we're going to input the read in
array which is created from this here so
we're counting the values in the array
now what we can do is get rid of this
and we can start an if statement here
now I'm going to say
if count doesn't equal read in count and
we're going to say echo comma and then
space after knee
afterwards sorry so what's happening
here we're counting the element in the
array and each element in the array is a
name so we're counting the names
essentially let's just declare this
count variable up here as zero okay so
if count which is this here doesn't
equal reading count then echo that then
we need to count plus plus at the end so
we're incrementing this count value each
time this will be 0 1 2 3 all the way up
to the amount of names that are in the
list then when we reach the last one
it's not going to it's not going to show
the comma so let's add another name in
let's say pizza click Submit
oh it actually has okay um so let's fix
this
so if countless look think about this
logically if count doesn't equal reading
count if count is smaller than
greater than yeah it'll be smaller than
so if count is smaller than reading
count let's have another name to the
list just do Daniel this time and click
Submit oh dear okay
hmm one change that to one perhaps oh I
think that might be the problem we'll
just keep adding Daniel there we go okay
so after a bit of fiddling around um
what we've done is we have created a
variable called count and assign the
value of 1 then we incremented this each
time but just before this we've created
the check to see if the count is smaller
than the amount of elements in this
flask the amount of names and and if it
is smaller then that means that's fine
we can get we can echo out a comma
otherwise if we've got to the last
element in the array then we want to not
not we don't de Becque or a comma
because it's silly echoing a comma in
the end
so after this tutorial and me making a
couple of mistakes and correcting myself
I'm sure you've learnt a thing or two so
that's the end of this tutorial
about reading in files with PHP