Introduction

In this post, we will discuss the switch statement and its flow in a C++ program. When a switch statement is executed, its expression is evaluated. If the value of the expression equals the case expression the flow is transferred to the action with the matching case expression.

Syntax

switch(SwitchExpression){
case CaseExpression1:
action1

break;
case CaseExpression2:
action2

break;
case CaseExpression3:
action3

break;
default:
defaultAction
}

 

Flowchart

 

Sample Program

/*************************
* C++ switch statement demo
*************************/

#include <iostream>
using namespace std;

int main()
{
    int operand1;
    int operand2;
    bool isValid=false;
    char mathOperator;
    int expResult;
    cout << "----Welcome to Simple Calculator-----" << endl;
    cout << "Please enter expression : " << endl;
    cout << "Example:" << endl;
    cout << "2" << endl;
    cout << "+" << endl;
    cout << "3" << endl;
    cout << "--------------------------------------" << endl;
    cin >> operand1;
    cin >> mathOperator;
    cin >> operand2;

    switch(mathOperator)
    {
    case '+':
        isValid=true;
        expResult = operand1 + operand2 ;
        break;
    case '-':
        isValid=true;
        expResult = operand1 - operand2 ;
        break;
    case '*':
        isValid=true;
        expResult = operand1 * operand2 ;
        break;
    case '/':
        isValid=true;
        if(operand2 != 0)
            expResult = operand1 / operand2 ;
        else
            cout << "Infinity!." << endl;
        break;
    default:
        isValid=false;
        cout << "Operator not supported" << endl;
    }
    if(isValid)
    {
        cout << "--------------------------------------" << endl;
        cout << "Result=" << endl;
        cout << operand1 << " " << mathOperator << " "
             << operand2 << " =  " << expResult << endl;
        cout << "--------------------------------------" << endl;
    }
    return 0;
}

 

Sample Run

—-Welcome to Simple Calculator—–
Please enter expression :
Example:
2
+
3
————————————–
1073
+
35451
————————————–
Result=
1073 + 35451 = 36524
————————————–

Process returned 0 (0x0) execution time : 11.207 s
Press any key to continue.