C Language Tutorial on Strings for Beginners Session 14 | Elprocus Video Lecture | Basics of C Language - Fundamentals of Programming - Software Development

the 14th session strings strings is an
alphabetical value provided in C program
basically a simple string works as an
array only so if we say an integer array
with certain size in it for this is
called as integer array flowed array of
size 6 we call it a floater and now we
do not call it as character array but we
call it as strings so what all we saw in
the iris of type float or integer the
same thing we'll be seeing in strings or
not so called as character array to work
in strings we need to know certain
predefined functions but before that
will take up certain programming
concepts in strings declaration of
strings how is it will be declaring the
strings now consider the string str
happens to be declaration will be given
in this way as you can see there are
certain contents in the string ABCDE and
certain 50 but how can you point out the
difference between the variable a and
the character e we are supposed to place
certain characters in this strings and
how can I consider a is a character when
compared to this a this a is an integer
variable and why can't i call this as
integer variable on what basis i can say
this is a character
by using a set of coats we can call them
as characters but not variables so
replacing three characters in the string
at the end I need to place a null
character though it may seem to be two
characters but compiler treats it as one
we call it as null character now when
you say printf the character comma at
the position of zero to block you can
see the value printed happens to be a
which is at zero the block likewise if
you say to you will be printing the 0 1
2 character which is see the fourth
carrot the third character which is of
null character is not at all displayed
on the screen certain compilers display
in this way certain compilers will known
display anything on the screen so by
using a loop for equal to 0 a less than
four and A plus plus if i print all the
characters over here will be a b c and
the null character in this way apart
from this kind of representation we can
even go for another representation which
is care str with certain characters in
it and that characters can be orbit
these are five characters and at the end
the null character comes by default to
prove that if i say less than five print
all the characters and we printing orbit
if I make it to six at the 6th 5th block
I have the null character again so it's
clear
that in this kind of representation I
need to place the null character
exclusively and in this kind of
initialization for a string it is not
necessary for me to place the null
character because the null character
comes by default as you can see have
been initializing my strings with
certain characters in it now I can
directly go for scanning them similarly
I can scan the values by using the same
furlough for a equal to 0 and L is then
Phi a plus plus this can if person see
the character and ampersand str of 8th
block now here i'll scan the values and
i'll print the values on the screen let
it be india and i will be printing india
on the screen so to scan a character
array or string the perfect word given
is a string we can go for the format
specifier person d in an integer array
will be saying percentage of format
specifier and the rest is quite the same
here it's person C because it is a set
of it is a character apart from using
the fur block we can directly go for
saying another format specifier which is
percentage but when you say percent is
remove all these things and simply say
the name of the array do not mention the
blocks don't mention the blocks and also
% s remove those things so now you are
scanning the entire string at it I am
NOT character by character so now when I
say
is displayed on the screen but the
problem when we use % s as our format
specifier problem we face is a V and
this is the third character that is a
space and EF are the five characters i
am trying to input them in my string as
you can see ABR two characters here for
two more characters making it as 4 and
the space is the fifth character so when
I print them when I scan them by using
the format specifier % s this is what
happens you can see the difference the
characters what all come after space are
lost if my input is this four characters
5th character 6th 7th character 8th 9th
10th over and all i am using 10
characters so because of the format
specifier % s I the compiler won't take
up all the characters which come after
the space up to this it is safe but from
the space is everything is lost to
overcome this problem go for using the
predefined functions get S along with
the name and put s along with the name
when you say this is a string str will
be displayed on the screen as it is so
three ways to scan the strings one is
user for loop and scan by using the
format specifier % c or simply use this
kind of statement along with the format
specifier percentage
but it holds a defect it does not accept
all the characters which come after this
face so the most common and very simple
way to scan for the strings is get us
and do print is put us these are very
common and quite simple pre different
functions which we can go for using now
we'll go for the pre different functions
what all we have in strings as you can
see the declaration happen in this way
in this way and in this way these are
the two types of declarations available
for Strings the common predefined and
general use predefined functions in
strings concept our spring cat string
concatenation string str rav4 string
reverse str Elian for string length str
UPR to get the string of per case and
similarly strcpy string copy strcmp
string comparison and str lwr string
lower we go for doing all these
predefined functions one by one the
first thing is we used hash include
stdio.h a void main and a string str
with will try to find out its length so
its face is 10 i will be giving certain
names by saying get us a CR this is
almost equivalent to saying scanf now
instead of putting the same string what
i will do this time is print the integer
with which we can get the str Elian
string length of s TR
but to use string length if we directly
compile this program will get an error
saying call to undefined function string
length in function main compiler is now
unable to understand from where string
length has come and so all these
predefined functions come from the
string dot H header file now when you
compile this program it is saying for me
to enter certain characters which are
some characters which we cannot count at
this stage but string length counts and
gives a particular integer that how many
character it holds one two three four
five six seven eight characters is what
it holds in str and is given on the
screen this is about string length now
coming to string reverse the name itself
says when I put it on the screen will be
displayed in this way India in India but
using str r EV string rivers for str the
string what I give like will be
displayed in Reverse format I n dia if
my input is a I DNI the output happens
to be the reverse of it which is India
so these are the pre different functions
which have been defined by dennis
ritchie in the header file called string
dot h string cat or string concatenation
for this I need two strings a CR one
which holds consider five characters
likewise str2 which holds around 15
characters get for the first ring and
put for the same string else can and
i'll print similarly get for string 2
similarly put it on the screen for
string to check the output at this stage
i say str1 and is displayed on the
screen str2 and is displayed on the
screen it's not only as TR 1 and 2 you
can give any kind of input after this if
i go for str CA T that is string
concatenation what exactly happens is
before that consider s1 and s2 are
normal variables normal variables which
hold certain data with this I mean what
has two holds copied into s 1 so this
means that what s one holds will be lost
and as to content will be placed in s 1
similarly in s2 I want to place the
content of s1 but here this doesn't mean
that the content of s2 is lost after
this when I say put us off s1 and put us
off s to check out the difference now
naming convention it is STR and STR of
one string cat include the header file
string dot H Mike str1 and str2 let's
look for the program because of that my
string one holds a and string 2 holds be
now after string concatenation this is
what happens in string to the content of
spring one is placed in string too but
that doesn't mean string two loses all
its data string 2 holds its data as well
as with string 1 the next predefined
function which is string cpy string copy
which is almost same as string
concatenation but the difference is
string 2 loses its data if string 1
holds a and string 2 holds be now
because of string copy the string to
what all it holds is lost and string 1
data is placed in string 2 when it comes
to string to it prints a because a is
copied into string 2 so the functions we
all used our string cat that is
concatenation string reverse that is
reversing the string string length which
gives
the number of characters we have and the
other functions will be considering them
in the next session