Switch Case

We use switch case when we have to check multiple conditions. It is similar to if else but it is more efficient than if else. It provided direct jump to the case statement

syntax of switch case :
switch(value)
{
    case 1 :
    // case 1 operations
    break;

    case 2 :
    // case 2 operations
    break;

    case 3 :
    // case 3 operations
    break;
}

Example 1️⃣ :

#include <iostream>
using namespace std;

int main() {

    int value;
    cout<<"Enter Value:";
    cin>>value;

    switch(value)
    {
        case 1 :
        cout<<"One";
        break;

        case 2 :
        cout<<"Two";
        break;

        case 3 :
        cout<<"Three";
        break;
    }

     return 0;
}

Output :

Enter Value: 1
One

Explanation :

Line 5 : Declare variable which name has value.
Line 6 : Enter value from user.
Line 7 : store value using cin object.
Line 9 : Use switch keyword to check multiple condition.
Line 10 : { open the body of switch case.
Line 11 : case 1 : and write the statement of case 1 and break the case 1 using break; keyword.
Line 15 : case 2 : and write the statement of case 2 and break the case 2 using break; keyword.
Line 19 : case 3 : and write the statement of case 3 and break the case 3 using break; keyword.
Line 22 : } close the body of switch case.

Switch case without using break statement

Example 2️⃣ :

#include <iostream>
using namespace std;

int main() {

    int value;
    cout<<"Enter Value:";
    cin>>value;

    switch(value)
    {
        case 1 :
        cout<<"One";

        case 2 :
        cout<<"Two";

        case 3 :
        cout<<"Three";
    }

     return 0;
}

Output :

Enter Value: 2
TwoThree

Explanation :

If there is no break statement then the cases after the matched case, all case are exexuted other than default case.

Example 3️⃣ :

#include <iostream>
using namespace std;

int main() {

    int value;
    cout<<"Enter Value:";
    cin>>value;

    switch(value)
    {
        case 1 :
        cout<<"One";
        break;

        case 2 :
        cout<<"Two";
        break;

        case 3 :
        cout<<"Three";
        break;

        default:
        cout<<"Not Matched";
    }

     return 0;
}

Output :

Enter Value: 5
Not Matched

explanation :

The condition inside the switch(value) is exexuted.
Then , it is matched with one of the case values, we execute that particular set of statements with it has matched.
After that case, we break out of switch.
If it does not match, we execute the default condition and come out of switch.

Example 4️⃣ :

#include <iostream>
using namespace std;

int main() {

    int a,b;
    cout<<"Enter Two Values:";
    cin>>a>>b;

    char op;

    cout<<"Which operations do you want to perform:(+, -, /, *): ";
    cin>>op;

    switch(op)
    {
        case '-':
        cout<<"a-b = "<<(a-b);
        break;

        case '+':
        cout<<"a+b = "<<(a+b);
        break;

        case '*':
        cout<<"a*b = "<<(a*b);
        break;

        case '/':
        cout<<"a/b = "<<(a/b);
        break;

        default :
        cout<<"Operation is not valid";
    }
     return 0;
}

Output :

Enter Two Values: 6,5
Which operations do you want to perform :(+, -, /, *): -
a-b = 1

**Explanation :

Line : 5 declare 2 variable which has aand b.
Line : 6 enter two values from user.
Line : 8 declare op variable.
Line : 10 Which operations do you want to perform:(+, -, /, *): from user.
The condition inside the switch(op) is exexuted.
Then , it is matched with one of the case values, we execute that particular set of statements with it has matched.
After that case, we break out of switch.
If it does not match, we execute the default condition and come out of switch.

Example 5️⃣ :

#include <iostream>
using namespace std;

int main() {

    int a,b;
    cout<<"Enter Two Values:";
    cin>>a>>b;

    char op;

    cout<<"Which operations do you want to perform:(+, -, /, *): ";
    cin>>op;

    switch(op)
    {
        case "-";
        cout<<"a-b = "<<(a-b);
        break;

        case "+";
        cout<<"a+b = "<<(a+b);
        break;

        case "*";
        cout<<"a*b = "<<(a*b);
        break;

        case "/";
        cout<<"a/b = "<<(a/b);
        break;

        default :
        cout<<"Operation is not valid";
    }
     return 0;
}

Output :

Enter Two Values: 9 9
Which operations do you want to perform :(+, -, /, *): #
Operation is not valid

**Explanation :