All language subtitles for 变量英文字幕

alright everybody we are moving on to variables

a variable is a container for a value

there's four different data types we'll discuss

strings integers floats and booleans

yes I know that's a silly name

variable behaves as if it was the value it contains

each variable should have a unique name

let's say we have a variable of first name

to assign a variable

you use the assignment operator of equals

for text a string is a series of text

this can be double quotes or single quotes

my own preference is double quotes

why don't you type in your first name

this variable a first name

will behave as if it was this value

this series of characters

so to demonstrate this I'm going to print

my first name variable

so place it within a print statement without quotes

that will print your first name

now you don't want this within quotes

because then you're literally printing

the word first name

you could use your variable along with some text

by using what is called an F string

that's the easiest way to display a variable

so you type F

menasetic quotes

the F means format

so let's say the word hello

then we will add our variable

we will insert our variable into this text

when using an F string

to do that you need a set of curly braces

then insert your variable

so the result is hello

whatever your first name is in my case bro

let's create another variable

let's say we have a variable of food

food equals think of your favorite food

for me I will type pizza

let's print the following

you like add a placeholder

again I'm using an F string

our variable of food

hello bro you like pizza

let's create an email

use your own email or makeup 1

let's say my email is bro

onetwothreeatfake.com

then let's print our email

your email is at a placeholder

display our email variable

your email is bro 1 2 3 at fake com

so these are strings

I'm going to add a comment that these are strings

a string is a series of characters

they can include numbers

but we treat them as characters

now we have integers

an integer is a whole number

an example of this could

somebody's age

how old are they

according to my YouTube statistics

many of you are between the ages of 18 through 24

let's say that I'm 25

let me zoom in a little

your integer should not be within quotes

because it would be a string then technically

if I would like to work with this variable

again I'll use enough string

let's say you are

add a placeholder

display our age variable

years old

you are 25 years old

another example of an integer could be a quantity

you are buying a certain amount of something

maybe I am buying 3 items

I wouldn't have half an item

this would be a float technically

rather than an integer

we are buying 3 of something

so let's print the following

you are buying

at a placeholder

display our quantity

items

you are 25 years old

you are buying 3 items

another example of an integer could be

an amount of people

let's say number of students

like a classroom

there are 30 students in our class

then we will print

your class has at a placeholder

students we will display the number of students

number of students

your class has 30 students

those are integers

their whole numbers

and again make sure they're not within quotes

because then technically they would be a string

integers we can use in arithmetic expressions

if they were strings we couldn't

then we have floats

float means floating point number

a float is a number but it contains a decimal portion

an example would be a price

what is the price of something 1099

let's print our price

print I'll use an F string

the price is at a placeholder

display our price

the price is 10 99

let's precede our placeholder with a unit of currency

I'll pick American dollars

but feel free to pick something else

the price is 10 dollars and 99 cents

so floats contain a decimal portion

what about a grade point average GPA

let's say my GPA is 3.2

then I will print

your GPA is

display our GPA

your GPA is 3.2

what about a distance

a distance can contain a decimal portion

5.5 km maybe

then I will print

you ran at a placeholder

display our distance

then I'll add km4km

or you could add mi for miles but I'll stick with km

you ran 5.5km

k then we have booleans

a boolean is either true or false

let's say we are a student

is student equals

if we are a student we could say that this is true

true starts with a capital T

if we weren't a student let's say we graduate

we could say that this is false

again the first letter is capital

booleans only have two options true or false

so let's say that I am a student

then I will print

are you a student

then we will display our Boolean value of a student

are you a student that is true

with bullion values

we really don't output them directly

you're more

likely to see them used internally within a program

such as when working with if statements

this is a topic we'll discuss in the future

so don't worry

you may see if

is student if this variable is true

then we will print the following

now we don't need to use enough string

we're not going to insert any variables

you are a student

if this were false we can add an L clause

where we will print

you are not a student

our variable of a student is true

we will print the if statement

you are a student

if this were false we will print whatever is within

else

you are not a student

let's think of a few more examples

is something for sale

like a car or a product of some sort

let's say that is true

I'll write another if statement

if for sale if this variable contains true

we will do the

let's print

that item is for sale

else if it's false we will print something else

that item is not available

for sale is set to true

this variable is true

we will print that item is for sale

else if it were false

we print that item is not available

one more example

let's say we have a Boolean variable of is online

is somebody online

I will set that to true

if is online if that's true we will print you are

online

else we will print

you are offline

is online is set to true

we will print you are online

else if it were false we print your offline

alright everybody so those are variables

a variable is a reusable container for a value

there's four basic data types for beginners

a string which is a series of text

integers which are whole numbers

floats

which are numbers but they contain a decimal portion

and booleans which are either true or false

their binary your assignment in the comments section

is to post four variables

post a string an integer a float and a boolean

try and think of a unique example if you can

and well everybody those are variables in Python