What is an Operator?
Operator :An operator is a symbol that performs a certain operation on a variable or expression. So far, we have used the = sign, which calls an assignment operator that assigns a value or expression from the right-hand side of the equals sign to a variable on the left-hand side.
Let's look at some of the use cases of these operators:
#include <iostream>
#include <conio.h>
// Program prints out value of a + b and x + y to screen
int main()
{
int a = 8; int b = 12;
std::cout << "Value of a + b is : " << a + b << std::endl;
float x = 7.345f; float y = 12.8354;
std::cout << "Value of x + y is : " << x + y << std::endl;
getch();
return 0;
}
The output of this is as follows:
Value of a+b is : 20 Value
of x+y is :20.1804
Let's look at examples for other operations as well:
#include <iostream>
#include <conio.h>
// Program prints out values to screen
int main()
{
int a = 36; int b = 5;
std::cout <<"Value of a + b is :" <<a+b<<std::endl;
std::cout <<"Value of a - b is : " << a - b << std::endl; std::cout <<"Value of a * b is : " << a * b <<std::endl; std::cout <<"Value of a / b is : " << a / b << std::endl; std::cout <<"Value of a % b is : " << a % b <<std::endl; getch();
return 0;
}
The output is as shown as follows
value of a+b is:41
value of a-b is:31
value of a*b is:180
value of a/b is:7
value of a%b is:1
Comparison operator
What are the Statements in C/C++ language?
A program may not always be linear. Depending on your requirements, you might have to branch out or bifurcate, repeat a set of code, or make a decision. For this, there are conditional statements and loops. In a conditional statement, you will check whether a condition is true. If it is, you will go ahead and execute the statement. The first of the conditional statements is the if statement.
The syntax for this looks as follows:
If (condition) statement;
The output is as follows: 36 is greater than 5
We check the condition if a is greater than b, and if the condition is true, then we print out the statement. we have the if...else statement, which is a statement that basically executes the alternate statement.
The syntax looks like this:
if (condition) statement1; else statement2
Let's look at it in code:
#include <iostream>
#include <conio.h>
// Program prints out values to screen
int main()
{
int a = 2; int b = 28; if (a >b)
std::cout << a << " is greater than "<< b<< std::endl;
else
std::cout << b << " is greater than "<< a<< std::endl;
getch();
return 0;
}
Here, the values of a and b are changed so that b is greater than a:28 is greater than 2. One thing to note is that after the if and else conditions, C++ will execute a single line of the statement. If there are multiple statements after the if or else, then the statements need to be in curly brackets, as shown:
if (a > b)
{
std::cout << a << " is greater than "<<b<<std::endl;
}
else
{
std::cout << b << " is greater than"<<a<<std::endl;
}
value of a+b is:41
value of a-b is:31
value of a*b is:180
value of a/b is:7
value of a%b is:1
+, -, *, and / are self- explanatory. However, there is one
more arithmetic operator: %, which is called the modulo operator. It returns
the remainder of a division. How many times is 5 contained in 36? 7 times with a remainder of 1.
That's why the result is 1. Apart
from the arithmetic operator, we also have an increment/decrement operator.
In programming, we increment variables often. You can do
a=a+1; to increment and a=a-1; to decrement a variable value. Alternatively,
you can even do a+=1 and a-=1; to increment and decrement, but in C++
programming there is an even shorter way of doing that, which is by using the
++ and -- signs to increment and decrement the value of a variable by 1.
#include <iostream>
#include <conio.h>
// Program prints out values to screen
int main()
{
int a = 36; int b = 5;
std::cout << "Value of ++a is : " << ++a <<std::endl;
std::cout << "Value of --b is : " << --b <<std::endl;
std::cout << "Value of a is : " << a <<std::endl;
std::cout << "Value of b is : " << b << std::endl;
getch();
return 0;
}
The output of this is as follows:
Value of ++a is : 37
Value of –b is : 4
Value of a is : 37
Value of b is
: 4
Consequently, the ++ or -- operator increments the value
permanently. If the ++ is to the left of the variable, it is called a
pre-increment operator. If it is put afterward, it is called a post-increment
operator. There is a slight difference between the two
If we put the ++ on
the other side, we get the following output:
Value of a++is : 36
Value of b --is: 5
Value of a is: 37
Value of b is
: 4
In this case, a and b are incremented and
decremented in the next line. So, when you print the values, it prints out the
correct result. It doesn't make a difference here, as it is a simple example,
but overall it does make a difference and it is good to understand this difference.
In this book, we will mostly be using post-increment operators. In fact, this
is how C++ got its name; it is an increment of C.
Logical operator
Comparison operator
A program may not always be linear. Depending on your requirements, you might have to branch out or bifurcate, repeat a set of code, or make a decision. For this, there are conditional statements and loops. In a conditional statement, you will check whether a condition is true. If it is, you will go ahead and execute the statement. The first of the conditional statements is the if statement.
The syntax for this looks as follows:
If (condition) statement;
Let's look at how to use this in code in the
following code. Let's use one of the comparison operators here:
#include<iostream> #include <conio.h> // Program prints out values to screen
int main()
{
int a = 36;
int b = 5;
if (a > b)
std::cout << a << " is greater than " << b << std::endl;
getch();
return 0;
}
The output is as follows: 36 is greater than 5
We check the condition if a is greater than b, and if the condition is true, then we print out the statement. we have the if...else statement, which is a statement that basically executes the alternate statement.
The syntax looks like this:
if (condition) statement1; else statement2
Let's look at it in code:
#include <iostream>
#include <conio.h>
// Program prints out values to screen
int main()
{
int a = 2; int b = 28; if (a >b)
std::cout << a << " is greater than "<< b<< std::endl;
else
std::cout << b << " is greater than "<< a<< std::endl;
getch();
return 0;
}
Here, the values of a and b are changed so that b is greater than a:28 is greater than 2. One thing to note is that after the if and else conditions, C++ will execute a single line of the statement. If there are multiple statements after the if or else, then the statements need to be in curly brackets, as shown:
if (a > b)
{
std::cout << a << " is greater than "<<b<<std::endl;
}
else
{
std::cout << b << " is greater than"<<a<<std::endl;
}
You can also have if statements after using else if:
#include <iostream>
#include <conio.h>
// Program prints out values to screen int
main() {
int
a = 28; int b =28; if (a > b)
{ std::cout
<< a << " is greater than " << b <<
std::endl;
} else
if (a ==b) {
std::cout
<< a << " is equal to " << b <<
std::endl;
}
else
{
std::cout
<< b << " is greater than " << a <<std::endl; }
getch(); return 0;
}
OUTPUT
28 is equal to 28
What is the Iteration in C/C++?
Iteration is
the process of calling the same statement repeatedly. C++ has three iteration
statements: the while, do...while, and for statements. Iteration is also
commonly referred to as loops.
The while loop syntax
looks like the following:
while
(condition) statement;
Let's look at it in action:
#include <iostream>
#include <conio.h>
// The program prints out values to screen
int main()
{
int a = 10; int n = 0;
while (n < a)
{
std::cout << "value of n is: " << n << std::endl;
n++;
}
getch();
return 0;
}
Here is the
output of this code:
value of n is :0
value of n is :1
value of n is :2
value of n is :3
value of n is :4
value of n is :5
value of n is :6
value of n is :7
value of n is :8
value of n is :9
Here, the value of n
is printed to the console until the condition is met. The do-while
statement is almost the same as a while statement except, in this case, the
statement is executed first and then the condition is tested
The syntax is as
follows:
do statement while
(condition);
You can give it a go
yourself and check the result.
The loop that is most
commonly used in programming is the for loop.
The syntax for this looks as
follows
for (initialization;
continuing condition; update) statement;
The for loop is very
self-contained. In while loops, we have to initialize n outside the while loop,
but in the for loop, the initialization is done in the declaration of the for
loop itself.
Here is the same
example as the while loop but with the for loop:
#include
<iostream>
#include
<conio.h>
// Program prints out
values to screen
int main()
{
for (int n = 0; n
< 10; n++)
std::cout << "value of n is:
" << n << std::endl;
getch();
return 0;
}
The output is the
same as the while loop but look how compact the code is compared to the while
loop. Also, the n is scoped locally to the for loop body.
We
can also increment n by 2 instead of 1, as shown:
#include<iostream> #include <conio.h>
// Program prints out
values to screen
int main()
{
for (int n = 0; n
< 10; n+=2)
std::cout << "value of n is:
" << n << std::endl;
getch();
return 0;
}
Here is the output of this code:
The value of n is
: 0
The value of n is
: 2
The value of n is
: 4
The value of n is
: 6
The value of n is
: 8
`
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