Git Tutorial 4: Undoing/Reverting/Resetting code changes Video Lecture | Git Tutorial: What is git / What is version control system? - Software Development

hello and welcome to core basics coding
tutorial and this tutorial we are going
to see how to undo or reset or revert
your code changes and get for this we
are going to first clone our github
repository in my previous tutorial I
created this test repository I am just
going to click here to copy the link and
in git bash I will run git clone come on
to clone the repository locally now I
have this Secord directory and if you
look at this directory I don't have any
taste director here but once I clone it
I will have it so now I got it
ok now I'm going to open this test
directory in 2py charm so I have opened
it here already I have my Hungary code
here you might be familiar with this
code if you have watched my previous get
tutorials all I'm going to do is make
some changes and show you how you can
undo those changes ok so the first item
we are covering is undoing your
uncommitted changes so let's say I
change this code and add one new line
alright so I am adding this new line I
am running the program and then I
realize that I am feeding too much junk
to my kid you know I don't want my kid
to look like this so I want to cut down
on his Pisa intake so I will undo this
one line alright for doing that I will
go to my git bash first run git status
come on I was not in this directory
that's why I give me that error so I'm
now in test directory running git status
it is showing me I have changed hungry
dot py file ok before this you see this
useful tip it says you can then get
check out - - filename to discard
changes in your working directory so I'm
just going to use this get check out - -
file name is hungry dot py hit enter
when I do that my Pisa change is gone
all right
now I can easily undo that change by
removing that last line but when you are
doing programming in real life you might
have hundreds of lines of code changed
for that you are not going to manually
undo all of those lines right it's very
cumbersome so that's why you you will
use git checkout - - command ok now what
if you have multiple files change so
again you have let's say ah this file
changed first of all and you have readme
file change as well as the you added
some garbage here and now when I do get
status I will see two Faiza change one
option is I do get checkout - - this
file name first and then the second file
name but there is a convenient option of
using dot when you do dot it is going to
undo all the files so when I do get
status here you see both of these files
are gone and when I open it here in my
py charm code editor PISA is gone and
that junk is gone alright so this was a
quick demo on how to undo uncommitted
changes but what if you have committed
changes so let me first commit some
changes all right so I have my PISA
change I am going to commit that so
always do get add to add your file to
staging area then do git commit - M
means message Fiza
alright this commits my change how do
you know it's committed you can always
run git log and in the git log it is
showing that this change is committed
with this particular commit ID okay life
is good so far I want to eat more junk
food and I will say eat burger ok cool
again go here and get ad now one thing
you notice I always do get ad and then
get do then do get commit right so there
is one easy option called get commit -
km now when i do - am the problem means
is gonna probably add this one as well
so ok i'm not going to do that so i will
just do it ad
hungry and then get - hamburger okay
clear it and again check it log and now
I have Pisa and burger both committed
good all right now what I want to do is
I want to undo this burger chain okay
now I can't run git checkout - - because
the change is already committed so for
this you can use git revert come on okay
now that command would need the commit
ID so I am going to just copy it so
double click here copy the commit ID and
then run git reword that particular
commit ID okay it's just showing the
summary that you are rewarding that
particular commit and you need to type
column Q to close this UI and once you
do that the change is committed so let
me verify okay you see that Berger is
gone okay and if you run git log here
you will see there was a burger change
and now there is a reward burger chain
awesome so this looks good so far now
one thing you might have noticed is when
I did get reward it directly committed
the change let's say I don't want to
commit the change I want to run get
reward and then I want to explicitly
committed okay you can do that by using
- and option so first let's look at log
okay and now let's say I want to undo
this work up this pizza chain okay so
first you need to copy this
okay and then do get every word - n so
it's the same command that we ran
previously but now we have - an option
when you do this or a let me show here
when you do this that change that P's
aligned is gone all right but the change
is not committed so if you do get status
you will see now that file is modified
it is uncommitted so now you need to
explicitly commit it you can review your
change and explicitly commit it and say
we work visa so now when you do get log
you will see the word Pisa here so the
difference between supplying a - n
option versus not supplying it is the -
an option will not commit your changes
versus if you don't supply anything it
will just commit the changes okay okay
now the third item we are covering today
is git reset so I have all this git log
history all right
this shows the history in time of how my
code evolved okay so in my code
evolution let's say I want to go back to
this status where I had Pisa and Burger
both okay I realized that whatever
changes I made after that they are not
useful and I want to undo those changes
okay so for doing that you can use git
reset command so first let me copy which
commit ID I want to go to so let's say I
want to go to this status on Friday
August 5 1954 so I will copy this and I
will do get our reset - - hard
let's commit ID and now I am when you
say git log you'll notice all those
river changes are gone and in your
working directory you are back to eating
peas and burger okay
so git reset is actually quite powerful
it takes you to any previous timestamp
in your code history but at the same
time it is destructive as well if you
make a mistake then you will just lose
all the changes so be very careful when
you are using git reset command alright
so that was all about undoing changes
and gate thank you for watching