Switch performs the code block that matches the case value. If the value matches none of the cases, the default block is executed.

Syntax:

switch ( integer/character expression )
{  
case {value 1} :  
do this ;
 
case {value 2} :  
 do this ;  
 
default :  
do this ;
 }

The expression after the switch can be either an integer or a character expression. Keep in mind that case labels should be unique for each case. If they are the same, it may cause an issue while running a programme. We usually use a colon at the end of the case labels ( : ). Each case is linked to a block. A block is a collection of statements that are grouped together for a specific case.

Example:

#include <iostream>
using namespace std;
 
int main()
{
    int i = 2;
    switch (i)
    {
    case 1:
        cout << "Statement 1" << endl;
        break;
 
    case 2:
        cout << "Statement 2" << endl;
        break;
 
    default:
        cout << "Default statement!" << endl;
    }
}

Output:

Statement 2

The post C++ Switch Case first appeared on Student Projects.

The if statement’s condition is always encased in a pair of parentheses. The set of statements that follow the if statement will be executed if the condition is met. Additionally, the statement will not be executed if the condition evaluates to false; instead, the programme will skip the enclosing portion of code.

Relational operators are used to define an expression in if statements. If the expression after the if evaluates to true, the statement contained in the if block will be carried out. However, if the if block is followed by an else block, a sequence of statements in the else block will be executed when the if block’s condition is false.

Syntax:

if ( condition ){
statements;}
 else {
statements;}

Example:

#include <iostream>
using namespace std;
 
int main()
{
    int age;
    cout << "Enter a number: ";
    cin >> age;
    if (age >= 50)
    {
        cout << "Input number is greater than 50!" << endl;
    }
    else if (age == 50)
    {
        cout << "Input number is equal to 50!" << endl;
    }
    else
    {
        cout << "Input number is less than 50!" << endl;
    }
}

Input:

Enter a number: 53

Output:

Input number is greater than 50!

The post C++ If Else first appeared on Student Projects.

Sequence Structure

Sequence structure describes the order in which a programme executes its instructions.

Selection Structure

The execution of instructions in accordance with the specified condition—which may be true or false—is referred to as a selection structure. It is possible to use selection structures in two different ways. Either if-else statements or switch case statements are used to accomplish these tasks.

Loop Structure

Until the condition becomes false, an instruction is executed in a loop, which is referred to as a loop structure.

The post Control Structure first appeared on Student Projects.

It’s them,

Input source

The direction of the bytes flowing in the input stream is from the input device (such as the keyboard) to the main memory.

Output stream

The output stream’s bytes go from the main memory to the output device in that order (for ex-display)

An illustration of how input and output are commonly carried out in C++

#include <iostream>
using namespace std;
 
int main()
{
    int num;
    cout << "Enter a number: ";
    cin >> num;                        // Getting input from the user
    cout << "Your number is: " << num; // Displaying the input value
    return 0;
}

Input:

Enter a number: 10

Output:

Your number is: 10

Significant Points

• The insertion operator is also known as the sign.

• The extraction operator is the symbol >>.

• cout is a printing keyword.

• Run-time input is taken via the cin keyword.

The post C++ Basic Input/Output first appeared on Student Projects.

At the bit level, operations are carried out using a bitwise operator. They translate our input values into binary format, process them using the appropriate operator, and output the results.

#include <iostream>
using namespace std;
 
int main()
{
    int a = 13; //1101
    int b = 5;  //101
    cout << "The value of a & b is " << (a & b) << endl;
    cout << "The value of a | b is " << (a | b) << endl;
    cout << "The value of a ^ b is " << (a ^ b) << endl;
    cout << "The value of ~a is " << (~a) << endl;
    cout << "The value of a >> 2 is " << (a >> 2) << endl;
    cout << "The value of a << 2 is " << (a << 2) << endl;
}

Output:

The value of a & b is 5
The value of a | b is 13
The value of a ^ b is 8
The value of ~a is -14
The value of a >> 2 is 3
The value of a << 2 is 52

Assignment Operators

Values are assigned using assignment operators. They will be incorporated into nearly every programme we create.

int a = 0;
int b = 1;

Inherent Operator Priority and Associativity

Operator priority

It assists us in solving an equation by allowing us to distinguish which operator comes before another. Think about the phrase a+b*c. Given that the precedence of the multiplication operator is higher than the precedence of the addition operator, multiplication between a and b will now be completed before the addition operation.

Associativity of operators

When two or more operators with the same precedence are combined in an expression, it aids in solving the expression. It aids in determining whether to begin solving the expression comprising operators with the same precedence from the left to the right or vice versa.

The post Operators in C++ Part III first appeared on Student Projects.

Relational operators are used to check the relationship between two operands and to compare two or more numbers or even expressions in cases. The return type of a relational operator is a Boolean that is, either True or False (1 or 0).

#include <iostream>
using namespace std;
 
int main()
{
    int a = 4, b = 5;
    cout << "The value of a == b is " << (a == b) << endl;
    cout << "The value of a < b is " << (a < b) << endl;
    cout << "The value of a > b is " << (a > b) << endl;
}

Output:

The value of a==b is 0
The value of a<b is 1
The value of a>b is 0

Logical Operators

To determine whether an expression is true or false, logical operators are utilised. The logical operators AND, OR, and NOT are the three. Although they are frequently used to compare expressions to determine whether they are satisfactory or not, they may be used to compare Boolean values as well.

• AND: it returns true when both operands are true or 1.
• OR: it returns true when either operand is true or 1.
• NOT: it is employed to change the operand’s logical state and is true when the operand is false.

#include <iostream>
using namespace std;
 
int main()
{
    int a = 1, b = 0;
    cout << "The value of a && b is " << (a && b) << endl;
    cout << "The value of a || b is " << (a || b) << endl;
    cout << "The value of !a is " << (!a) << endl;
}

Output:

The value of a && b is 0
The value of a || b is 1
The value of !a is 0

The post Operators in C++ Part II first appeared on Student Projects.

Arithmetic Operators

Mathematical operations like addition, subtraction, etc. are carried out using arithmetic operators. They could be binary or unary. Several of the basic arithmetic operators include

#include <iostream>
using namespace std;
 
int main()
{
    int a = 4, b = 5;
    cout << "The value of a + b is " << a + b << endl;
    cout << "The value of a - b is " << a - b << endl;
    cout << "The value of a * b is " << a * b << endl;
    cout << "The value of a / b is " << a / b << endl;
    cout << "The value of a % b is " << a % b << endl;
    cout << "The value of a++ is " << a++ << endl;
    cout << "The value of a-- is " << a-- << endl;
    cout << "The value of ++a is " << ++a << endl;
    cout << "The value of --a is " << --a << endl;
}

Output:

The value of a + b is 9 
The value of a - b is -1
The value of a * b is 20
The value of a / b is 0 
The value of a % b is 4 
The value of a++ is 4   
The value of a-- is 5
The value of ++a is 5
The value of --a is 4

The post Operators in C++ Part I first appeared on Student Projects.

Data types specify the kinds of data that a variable can store; for instance, an integer variable can store data of that kind, a character variable can store data of that type, etc.

In C++, there are three categories for data types:

Built-in data types

These pre-defined data types for a language could be used right away by the programmer.

Int, Float, Char, Double, and Boolean are a few examples.

User-defined data types

The user itself defines these data kinds. Class, Struct, Union, and Enum are some examples.

Derived data Type

The basic built-in data types are the ancestors of these data types.

Array, Pointer, and Function are some examples.

Some of the popular built-in data types and their applications are:

Constants in C++

Constants are immutable; once they are initialised in a program, a constant variable’s value cannot be changed.

#include <iostream>
using namespace std;
 
int main()
{
    const float PI = 3.14;
    cout << "The value of PI is " << PI << endl;
    PI = 3.00; //error, since changing a const variable is not allowed.
}

Output:

error: assignment of read-only variable 'PI'

The post C++ Data Types & Constants first appeared on Student Projects.

There are various sorts of variables in C++.

Here are a few of them:

• Integers (whole numbers) without decimals, such as 63 or -1, are stored in integer variables specified with the keyword int.
• Floating point numbers with decimals, such as 79.97 or -13.26, are stored in floating point variables specified using the keyword float.
• Single characters, such “A” or “z,” are stored in character variables specified with the keyword char. Char values must be enclosed in single quotation marks.
• When the bool keyword is used to define a boolean variable, it stores a single value that represents either false or true, 0 or 1.

Declaration

A variable cannot be declared without its data type being mentioned. What we want to store in the variable and how much space we need it to hold will determine the data type of the variable. Declaring a variable has the following simple syntax:

data_type  variable_name;

Identifying a Variable

Anything can be referred to as a variable. However, there are several guidelines we must adhere to while naming a variable:

• In C++, variable names can have any length between 1 and 255 characters.
• Only alphabetic characters, numbers, and underscores (_) are permitted in variable names.
• A digit cannot begin a variable.
• A variable’s name cannot contain any white space.
• Names of variables are case-sensitive.
• No special characters or reserved keywords should be present in the name.

Variable Scope

A variable’s scope refers to the area of a programme where its presence is permitted. Variables can be divided into two categories according to their scope:

Local variables:

Local variables can only be evaluated from the specific function they are declared inside the braces of.

Global variables:

Global variables can be accessed from anywhere and are declared outside of any function.

Example:

#include <iostream>
using namespace std;
 
int a = 5; //global variable
 
void func()
{
    cout << a << endl;
}
 
int main()
{
    int a = 10; //local variable
    cout << a << endl;
    func();
    return 0;
}

Output:

10
5

The post C++ Variables first appeared on Student Projects.

Comments can be singled-lined or multi-lined.

Single Line Comments

• Single-line comments are preceded by two forward slashes (/).
• Any information after the slashes / on the same line will be disregarded (not performed) because it is unparsable.

A single-line comment is used in this example.

#include <iostream>
 
int main()
{
    // This is a single line comment
    std::cout << "Hello World";
    return 0;
}

Multi-line comments

• A multi-line comment begins with /* and terminates with */.
• The compiler will discard any information between /* and */.

A multi-line comment is used in this example.

#include <iostream>
 
int main()
{
    /* This is a
    multi-line
    comment */
 
    std::cout << "Hello World";
    return 0;
}

The post Comments in C++ first appeared on Student Projects.