The document explains how switch statements work in programming, particularly in C++. It details the structure of a switch statement, the function of the break and default keywords, and provides an example of using switch to determine the day of the week. The break keyword allows for efficient execution by terminating the switch block upon finding a match.

1. SWITCH CASES
Presented by BARANI G.
1

2. Switch cases:
◦ The switch statement evaluates an integral expression and chooses one of
several execution paths based on the expression’s value.
◦ In other words, a Switch statement provides a convenient way of selecting
among a (possibly large) number of fixed alternatives.
2

3. General form:
switch(expression) {
case x:
// code block
break;
case y:
// code block
break;
default:
// code block
}
3

4. How switch statements work:
◦ The switch expression is evaluated once.
◦ The value of the expression is compared with the values of each case.
◦ If there is a match, the associated block of code is executed.
The break and default keywords are optional.
4

5. Flow chart of switch statement:
5

6. The break keyword:
◦ When C++ reaches a break keyword, it break out of the switch block.
◦ This will stop the execution of more code and case testing inside the block.
◦ When match is found, and the job is done, it’s time for a break. There is o need
for more testing.
A break can save a lot of execution time as it ignores the execution of all the
rest of the code in the switch block.
6

7. The default keyword:
◦ The default code specifies some code to run if there is no case match.
◦ The default keyword must be used as the last statement in the switch, and it
does not need a break.
7

8. Example: Day of the week
#include <iostream>
using namespace std;
int main() {
int day = 5;
switch (day) {
case 1:
cout << "Monday ";
break;
case 2:
cout << "Tuesday";
break;
8

9. case 3: Cont…
cout << "Wednesday";
break;
case 4:
cout << "Thursday";
break;
case 5:
cout << "Friday";
break;
case 6:
cout << "Saturday";
break;
9

10. case 7: Cont…
cout << "Sunday";
break;
default :
cout<< "Invalid input" ;
}
return 0;
}
OUTPUT:
Friday
10

11. Thank you!
11