Write Your First Program in C++
CodeHelp - by faizan
This is the 2nd lecture of our DSA series. We will see how a program runs and what does
each line mean in this lecture. This is how the compilation process work So it is compiler
which makes it possible for us to run a source code. Coding Ninjas has supported us in
providing this amazing DSA course to you. Courses are available in both Hindi and English.
you need an IDE to write, run and execute a code. There are many IDEs out there -
CodeBlocks, VsCode and many more - which you do n't even need to install Replit is one of
them. You can directly create a C++ there and run it using Replit. In C++, many namespaces
are there which have cout functions in them so if we want to use cout , we have to add this
file to our code. We use these signs to output the result into standard namespace. If you will
use > > by mistake by mistake, then it will give you compilation error So we use this operator
to display output.
We are going to talk about data types and variables. Whenever you have to story any
information or data in the memory. You have to mention what type of data it is and how
much memory it will take. For eg- int a = 5, a is a variable in memory which is of int type and
it has value 5 in it. We have certain rules which we have to follow when we are giving
names. There is a function named sizeof , which will tell you about the space being used by
any variable. In memory, first 29 bits will have 0, and last 3 bits will be 101, so in memory the
first 29 bit will have 0 and the last 3bits will have 101. We have a way to story multiple
characters but we will see that in upcoming lectures. In c++, all the characters are mapped
to some ASCII value in memory. We will just store binary form of ASCII value of any
character. If we have 4 different bytes with some binary value, how will compiler know
whether it is a single Int value of 4 separate char values ? Compiler will come to know from
data types which we used when we declared any variable. This process of converting one
data type into another is known as type casting.
There are few steps which I have to follow while storing a negative number. Let 's say the
number is -5 1st - Ignore the negative sign 2nd - Convert into binary representation = 101
3rd - Take 2 's complement and store it Now we can store negative numbers simply too, by
just using their first bit as their sign. With this our maximum value will be limited to 2^31 -1
instead of 2^32 -1. 2/5 will give 0 and not 0. 4 , why ? because you are storing your answer
in a int variable. To get answer in float, store it in a float variable. If you want to check
CodeHelp - by faizan
This is the 2nd lecture of our DSA series. We will see how a program runs and what does
each line mean in this lecture. This is how the compilation process work So it is compiler
which makes it possible for us to run a source code. Coding Ninjas has supported us in
providing this amazing DSA course to you. Courses are available in both Hindi and English.
you need an IDE to write, run and execute a code. There are many IDEs out there -
CodeBlocks, VsCode and many more - which you do n't even need to install Replit is one of
them. You can directly create a C++ there and run it using Replit. In C++, many namespaces
are there which have cout functions in them so if we want to use cout , we have to add this
file to our code. We use these signs to output the result into standard namespace. If you will
use > > by mistake by mistake, then it will give you compilation error So we use this operator
to display output.
We are going to talk about data types and variables. Whenever you have to story any
information or data in the memory. You have to mention what type of data it is and how
much memory it will take. For eg- int a = 5, a is a variable in memory which is of int type and
it has value 5 in it. We have certain rules which we have to follow when we are giving
names. There is a function named sizeof , which will tell you about the space being used by
any variable. In memory, first 29 bits will have 0, and last 3 bits will be 101, so in memory the
first 29 bit will have 0 and the last 3bits will have 101. We have a way to story multiple
characters but we will see that in upcoming lectures. In c++, all the characters are mapped
to some ASCII value in memory. We will just store binary form of ASCII value of any
character. If we have 4 different bytes with some binary value, how will compiler know
whether it is a single Int value of 4 separate char values ? Compiler will come to know from
data types which we used when we declared any variable. This process of converting one
data type into another is known as type casting.
There are few steps which I have to follow while storing a negative number. Let 's say the
number is -5 1st - Ignore the negative sign 2nd - Convert into binary representation = 101
3rd - Take 2 's complement and store it Now we can store negative numbers simply too, by
just using their first bit as their sign. With this our maximum value will be limited to 2^31 -1
instead of 2^32 -1. 2/5 will give 0 and not 0. 4 , why ? because you are storing your answer
in a int variable. To get answer in float, store it in a float variable. If you want to check
