Objective-C Tutorial - Lesson 2: Part 2: Programming Basics and Vocabulary Video Lecture | Learn and Understand: Objective C (English) - Web Development

here's all the different data types
there's int int that's an integer it's
just whole numbers and the size is 4
bytes
now there's unsigned integers an
unsigned integer I'll be going over
what's the difference between sign and
sign in the next slide
that's also 4 bytes now there's float
which is a floating point number and
that allows you to have a number of
decimals behind the number and that's
also 4 bytes now double is a double
precision floating point number and that
lets you do massive amounts of decimals
if you're dealing with really big
numbers you're gonna use a double that
takes up 8 bytes
now char it that's a character that's
just one single letter like a B or C
that takes up one byte and then their
string um it is a it's a string and then
the example this is a string it depends
on how many characters you have for what
size it is and then there's bull and
that really isn't like data types really
but I decided to add in here because it
kind of it goes along with this um
that's a bullying and it's true or false
so if you're gonna be doing canning in
an example or program oh like yes or no
like do you want to let's say turn on
the camera for like photobooth that type
that type of application you would do
one as yes and zero as you know so if
you do that it would be four bytes
because you're using num an integer but
you can also heard about people putting
it adds character to save bytes but
that's really if you're just trying to
make like a super fast application
but pretty much will be four bytes or if
you use a character will be one byte but
you won't really have to worry about how
many bytes the boolean is now sign
you're inside an integer
most of those they did have extreme
limits of how much the numbers that they
can handle for an integer it's two
billion 147 or yeah 147 million four
hundred three thousand six hundred
forty-seven positive and negative so by
default all variable types are signed so
if you don't you don't have to say
signed int you can just put int and it
automatically says it's signed now if
you're dealing with a really really
large number for some reason you can
make it unsigned int and then that
allows that maximum number of variables
to be added all the positive so it's now
four billion 294 million nine hundred
sixty seven thousand two hundred ninety
four but that's only if you really need
that maximum capacity is really the only
time you'll be using the signed run side
now initialization this is reserving
memory for a variable
first off you say the type of variable
so in this case int and then you do the
name and integer semicolon now also in
the initialization you can assign a
number to it so you can do int and
integer and equal signs in programming
it doesn't actually mean equal it
actually just is pretty much is so an
integer is 42 equals equals is so if
you're going like two plus three equals
five it'd be two plus three equals
equals five so when you actually wanted
to say be like equals the afternoon is
two but for most things because equals
is used so much in objective-c it's just
one equal sign so you can assign a
number with it right here in the second
one and then the last one there it's int
and integer and then comma and integer
to its indigo and so you initialize two
variables and a time they're now equal
is the assignment operator I already
went over that uh
so when you see equal and pretty much is
say in your head is instead of equal and
then semicolon vital vital piece a lot
of errors early on are just for from
forgetting the semicolon but it tells
the computer when you're done with a
statement
now operators they perform operations on
data so the plus is addition subtraction
is the - asterisk is multiplication
slash is division that's pretty simple
last one you may not be familiar with
that's the modular modular is the result
the result is the remainder from integer
division of first the first operand by
the second so if it was 15 divided by 4
4 goes into 15 3 times and with a
remainder of 3
so the modulo for that would be 3 so
it's just it's really just the remainder
of division of integers if the value of
the second operand is 0 the behavior of
modulo is undefined because you can't
divide something by zero now we're going
to be going into Xcode to actually do
some