Linux - If else statement

now let us check how we can use this if

L statement into our programs so

generally as I said if a statement can

be used in whenever we are going for

making any particular decision so as for

the you know the programs or ask for the

cases generally you will have or as per

the conditions you have you have to take

multiple decisions a program basic

offense condition will have if standard

with else called as I fi that is means

if-else phoenician we are using so if

suppose we have multiple condition

correct like if else and if again if or

else that is true value again I have

some program if not then also I have

program than the other now I can take an

example there is a general case in

general case a person can be a male or a

female if not female that will be a

transgender that is out generally we

should have right so he can be a male or

a female or a transgender so if he is

not a male or female so automatically it

will go to the default value that is a

transgender so the same thing we can use

into this kind of statement means we

have a third output if any of the cases

is not true one and case two is false so

the condition three will automatically

default Li accepted that is the if as a

Phi statement the next we have that is

if else is else fi means is this a

nested statement we have like if suppose

we have statement inside a statement

this is called as a nested statement so

a program contain you know values inside

that also we have multiple values for

example I can say what you want to eat

veg or non-veg so this is it to

condition you have either you can go for

an option one or option two again in

option two like which we have multiple

options whether you want to have some

item related to the rice or any

particular chapatis so this is again the

two of the options you have so whenever

you have options under an option that is

called as an nested statements so if you

are using a nested kind of program if

you have nested statements you can go

for if else--if as fi statements so

these are the three type of statements

under levy

while creating a program depending upon

the conditions you have into the program

so let us check our particular examples

all of these three programs which we are

going to use into the shell so here I'm

going to start with your decision-making

and I'm going a simple if' statement

where I'll begin creating on a search

file and here we are going to start with

your comment I'm going to add so that it

will come to know which now come on down

using so that is if I have statement I'm

going to use ok and here a keen what I'm

going to do is here I'm going to define

a variable and I'm going to add a value

into it so I have added a value like a

equals to 10 same thing I can also add

the value for B so I have added the

value of B equal to 20 and I want to

check whether this values are equal or

not so a simple program I'm writing here

so for that first I'll define the

condition in such a way I'll define if

under the closed and open square

brackets you need to define dollar a

that is my first variable equals 2

equals 2 we can use anybody color no

variable commands we can be and again

you can define the space that is done so

if this is true then you will be

refining echo what values are

Iker right so either you can define in

such a way or you can even call the

values first I'll define in such a way

and for ending this I'll be using

right

and I'll save this and we'll come out of

it

and again I'm going to run the same flow

so as those files are not equal orthopod

the variables are not equal that's the

reason we haven't got anything over here

now if both the lines or body variables

are equal not for example I'll just

change it any one only variable this one

to 20 and it cannot save it and again we

can check so you are getting the message

both variables are

we can we can use this in such a way we

can also call the very poor we can also

get the variables from the users as well

like we have used into our earlier

programs like if as such I'll also

define it in tubby

I want to take the data from the user so

echo first number okay read a and echo

the second number rich be okay then we

can save this and mode of it

I've just defined the the value so I

just need to remove that as well so I'm

just going to remove the thing okay so

save it and now I'm going to run the

same one if start as such first value is

two second value is 2 I'll get beads

message if I can I run the same and if I

mean I get the different values

I won't give get any particular message

that means they are not equal but see we

have used a condition but if you are

using the simple kind of condition I

won't be able to get any message if I do

do not have the same values or you know

my equation or the condition which I

have that is true

I'll get the you know output but if

there is no true so I won't get any

particular message on the screen so for

that we can again move for your

different variable sorry different kind

of your we can say like decision making

which is called as if else know for

example we are defining the value for

true value as well as will define thee a

nation for default values as well so for

that again I can use a different command

or you know I can use the same file as

such we have defined that if a equals to

B then we should print echo what values

are equal if suppose this is not true

condition so what you will have now what

I can do is I can insert here I just

change this a file and I'll add else if

it is not true

then we should get a message called as

let's just define tap echo

what

values

are not equal right so this is the

message I should get and if you get this

message that means this message is your

aunt in Dubai or we can also add it here

that will come to know this is the now

statement we are adding and due to which

this complete you know the statement we

have a decision making we have we are

using here this EF else

statement okay by just by adding the

else value so once we have done with

this once we have added default value

again we need to define FY once we are

handing over here just save it and again

I'm going to run the same file as such I

have taught essage to three now you can

see it is showing you what values are

not equal

now same way if I run I have not a set

and I give the same values if I give the

same values three and three it will give

me both values are equal so it is

accepting both t you know true and for

all conditions and giving the output as

per thee decisions you have so this we

have seen about here if-else statement

but sometimes your inner programmers but

lengthy and you need to define multiple

and L statement that's called as your

nested statement that we are going to

see here so for that altogether I'll be

using some other file or we can say some

other particular file so I'm just going

to take other example like 40 nestor

decision-making or we can see um lost

position thank you right not as such now

for that I'll be using a variable that

is a I'll be using I'll add some word to

a

or what I can do is I can add something

like word

variable I'm going to add it with E now

I'm going to set a condition if

this variable which I have inserted it

is word is equal to equal to the B if it

is not a if it is equal to B then what

we are going to do is

okay so I have used a double bracket so

I'll closing with double square bracket

itself then what the output I should go

I should get get the output as echo the

condition is true for example and then

if not then if else or else--if we can

use self if this is not true then this

can be a case where your unified space

your space your word is equal to equal

to your letter a right and then close

just brackets if it is fine then the

output what we should get that is the

condition as

this was because it is not same as your

be sorry or equal to your

here we can see if it is true okay this

is the false condition because in this

case this is matching with your a so

here we have set the other condition

that if it is equal to a the condition a

is true I'll just define so that I can

come to know which condition is correct

or which condition is having a true

value so for that I'll just define the

condition matches with B right well B so

it's true right so if here again I'll

define the condition matches to a value

so is it true now we have to find two

values like you know it is a gues

matches with two a so again it will be

true it matches to pre again it is true

now whatever doesn't matter anything

correct so for that I can define else if

both are not matched so we should you

find the condition what condition are

not matched what conditions a and B are

we can define any you know what are they

you know the output you want you can

define so both end behavior the

conditions are not matched

and so it's false right so this is what

exactly I have now cane I'll end it by

using the f5 so this kind of statement

where you have multiple statement

multiple conditions this can be called

as your

if

as if that is you can define as e.l.f

and yer else and then again you're a

farm right so which we have seen now let

us check the output of this again I'm

going to run it with your wise decision

rod and such a is true right so as we

have seen like the value which I have

added to my world

the value which I've added to my world

variable was a now if I make any changes

to it like if I make it to support

called as P

so we can check it by giving the command

decision so it's showing you the B is

true but if I change and I'll change the

world as C so it should not more match

body conditions and it should give me D

this particular message that both are

not met and it's false now button exists

false so this is how generally we create

a multiple statements multiple decisions

then we can we can also do entity while

which we have created earlier F 1 F 1

and I'm going to do as such so we have

now here

else if statement right if suppose I

have multiple conditions like I have a

condition like

you can see a co first number is say B

number is equals to B then the values

are equal and then I can I'm going to

add one more line here now for this I

can just what I can do is I can save as

copy of this file itself so I just copy

the PI F dot s such file with the name I

have to dot H file let us see here VI I

have to roll as such so I'm going to

make the changes so that this particular

whole you know the decision-making is

done by using AF LIF and

else right so for that I just remove

this line now I'll define multiple

conditions to it where I have also

defined the condition I have I'm going

to add one more

you

nation here I'm going to add echo

thar the number right I'll define dark

number here

read see alright so again equals two

feet and both values are equal F then we

can get the Pokemon then we can define

LF you can get echo

can also set the condition for your

elsif and less as we have done into the

earlier one you can also define it as

else if again the conditions we need to

define

if dollar a value equals $2 see

if it is the same then what we need to

type is then we should get in message

called as echo

what value

a and C are equal

and here I will make a changes

what values of a n

we are equal right so if it's not so

both values are not equal this will be

the case I'm going to add hit enter as

such I F 2 dot Sh first number 2 second

number 3

third number 4 so I just showing you 3

are not equal again if I use the I have

to not as such first value is 2 second

value is 3 hard values again 2 so it is

showing you a and C are equal right same

way if I give come on

as I of 2 dot SH and first value 2

second value 2 third value is different

it will show you a and B are equal but

this is the way how we can create nested

you know if conditions into the arm your

decision making so this is how generally

vision program into the script so the

last option generally we have that is

how we can use a case a set so the case

as such we are going to see into the

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