The switch statement in C++ is a control statement that allows a program to execute different code blocks based on the value of a variable or an expression. It is a powerful tool that can simplify complex decision-making processes in a program.
The switch statement works by evaluating the value of an expression and then comparing it to a series of case labels. If the value of the expression matches a case label, the code block associated with that label is executed. If no case label matches the value of the expression, the default code block is executed.
Here is the basic syntax of the switch statement:
switch(expression) {
case label1:
// code block 1
break;
case label2:
// code block 2
break;
...
default:
// default code block
}
The expression in the switch statement can be of any data type, including integers, characters, and enumerations. The case labels must be constant expressions that are compatible with the data type of the expression.
Each code block in the switch statement must end with a break statement. This is because the switch statement will continue to execute code blocks until it encounters a break statement or the end of the switch statement.
Here is an example of how the switch statement can be used in a program:
#include <iostream>
using namespace std;
int main() {
int day;
cout << "Enter a number between 1 and 7: ";
cin >> day;
switch(day) {
case 1:
cout << "Monday" << endl;
break;
case 2:
cout << "Tuesday" << endl;
break;
case 3:
cout << "Wednesday" << endl;
break;
case 4:
cout << "Thursday" << endl;
break;
case 5:
cout << "Friday" << endl;
break;
case 6:
cout << "Saturday" << endl;
break;
case 7:
cout << "Sunday" << endl;
break;
default:
cout << "Invalid input" << endl;
}
return 0;
}
In this example, the program prompts the user to enter a number between 1 and 7. The switch statement then evaluates the value of the variable day and executes the code block associated with the corresponding case label.
The default code block is executed if the value of day does not match any of the case labels.
The switch statement is a powerful tool that can simplify complex decision-making processes in a program. It is important to use it correctly and to always include a default code block to handle unexpected input.