What is switch case
When it comes to making decisions in programming, conditional statements are essential. Among these, the switch-case statement stands out as a powerful tool for handling multiple possible outcomes efficiently. In this guide, we’ll delve into the world of switch-case statements in the C programming language. We’ll cover everything you need to know to implement and use switch-case statements effectively in your C programs.
A switch case statement in C is a branching mechanism that allows you to evaluate a specific expression and choose the appropriate code block to execute based on the value of that expression. It’s particularly useful when you have a variable that can take different values, and you want to perform different actions based on those values.
Syntax: -
switch(expression) {
case value1:
// if expression == value1 than code will execute
break;
case value2:
// if expression == value2 than code will execute
break;
// more cases…
default:
// code to execute if no cases match
}
Working of switch-case
When a switch-case statement is encountered, the expression is evaluated, and the program jumps to the corresponding case label. Once the code block for that case is executed, the break statement is used to exit the switch block. If no break statement is present, the program will “fall through” to the next case and continue executing until a break is encountered.
The default statements
The default statement serves as a catch-all option in a switch case statement. It is executed when none of the case labels match the value of the expression being evaluated. This is useful for handling unexpected or unhandled cases.
Use of break
The break statement is essential for preventing fall-through behavior’s in a switch case statement. Fall-through occurs when there is no break statement after a case label, causing the program to continue executing subsequent case blocks even if their conditions are not met.
Write a program to implement grade calculator for student by using switch case: –
#include <stdio.h>
#include <conio.h>
void main() {
char grade;
clrscr();
printf("Enter your grade: ");
scanf(" %c", &grade);
switch (grade) {
case 'A':
case 'a':
printf("Excellent! \n");
break;
case 'B':
case 'b':
printf("Good job!\n");
break;
case 'C':
case 'c':
printf("Satisfactory.\n");
break;
case 'D':
case 'd':
printf("Needs improvement.\n");
break;
case 'F':
case 'f':
printf("You need to work harder.\n");
break;
default:
printf("Invalid grade.\n");
break;
}
getch();
}
Output: -
Enter your grade: A
Excellent!
[program terminated]
Write a program to implement simple calculator by using switch case: –
#include <stdio.h>
#include <conio.h>
void main() {
double num1, num2;
char operator;
clrscr();
printf("Enter two numbers: ");
scanf("%lf %lf", &num1, &num2);
printf("\nEnter an operator (+, -, *, /): ");
scanf(" %c", &operator);
switch (operator) {
case '+':
printf("Result: %.2lf\n", num1 + num2);
break;
case '-':
printf("Result: %.2lf\n", num1 - num2);
break;
case '*':
printf("Result: %.2lf\n", num1 * num2);
break;
case '/':
if (num2 != 0) {
printf("Result: %.2lf\n", num1 / num2);
} else {
printf("Error: Division by zero.\n");
}
break;
default:
printf("Invalid operator.\n");
break;
}
getch();
}
Output: -
Enter two numbers: 15 30
Enter an operator (+, -, *, /): +
Result:
45
[program terminated]
Write a program to check the day of week by given number by using switch case: –
#include <stdio.h>
#include <conio.h>
void main() {
int day;
clrscr();
printf("Enter a day number (1-7): ");
scanf("%d", &day);
switch (day) {
case 1:
printf("Sunday\n");
break;
case 2:
printf("Monday\n");
break;
case 3:
printf("Tuesday\n");
break;
case 4:
printf("Wednesday\n");
break;
case 5:
printf("Thursday\n");
break;
case 6:
printf("Friday\n");
break;
case 7:
printf("Saturday\n");
break;
default:
printf("Invalid day number.\n");
break;
}
getch();
}
Output: -
Enter a day number (1-7): 4
Wednesday
[program terminated]
Conclusion
Switch-case statements are a powerful tool in C programming that allow you to efficiently handle multiple scenarios based on the value of an expression. By understanding the syntax, working principles, and best practices, you can wield this construct to write cleaner and more organized code. Whether you’re building a menu-driven application or processing different cases, switch-case statements provide a structured approach to decision-making.
Use of continue and goto statements in switch case
When it comes to programming in C, understanding control flow is essential. Two important statements that affect the control flow of a program are the “continue” statement and the controversial “goto” statement. Before we dive into the specifics of the “continue” and “goto” statements, let’s briefly discuss control flow. It determines how the program progresses from one line of code to another based on conditions and loops.
The continue Statement
The “continue” statement is a control flow statement used within loops to skip the rest of the current iteration and move on to the next one. It’s particularly handy when you want to avoid executing a certain part of code for a specific condition without terminating the loop entirely.
For instance, imagine you’re iterating through a list of numbers and want to skip printing even numbers. You can use the “continue” statement to achieve this by instructing the program to move to the next iteration if the current number is even.
- Skip Current Iteration:
Thecontinuestatement is used within loops to immediately jump to the next iteration, skipping the remaining code in the current iteration. - Loop Context:
It’s most commonly used in loops, such asfor,while, anddo-while, to control the flow of the loop’s iterations. - Specific Conditions:
Thecontinuestatement is often employed to skip certain parts of the loop’s body when a specific condition is met. - Incremental Steps:
It’s beneficial when certain iterations require specific actions, such as incrementing counters or performing calculations, while others can be skipped. - Enhanced Efficiency:
By avoiding unnecessary processing, thecontinuestatement can enhance the efficiency of loop execution. - Iteration Continuation:
After encounteringcontinuestatement, the program proceeds directly to the next iteration, bypassing any code following thecontinuestatement in the current iteration. - Common Usage:
An example scenario is skipping processing for specific values in an array or collection and continuing with the remaining elements. - Readable Code:
Proper usage ofcontinuestatement can lead to more readable and concise code, as it allows for clearer expression of intended logic. - Avoid Nested Loops:
Whilecontinuecan be used in nested loops, its use can sometimes lead to complex control flow that may be harder to understand. - Balanced Approach:
Whilecontinuestatement can be a useful tool, it’s important to use it judiciously and strive for code that’s easy to understand and maintain.
#include <stdio.h>
int main() {
int choice;
for (int i = 0; i < 5; i++) {
printf("Enter choice: ");
scanf("%d", &choice);
switch (choice) {
case 1:
printf("Option 1 selected.\n");
continue;
case 2:
printf("Option 2 selected.\n");
continue;
default:
printf("Invalid option.\n");
break;
}
}
return 0;
}
Output: -
Enter choice: 1
Option 1 selected.Explanation:
In this program, the user is prompted to enter a choice. If the choice is 1 or 2, the respective option is printed, and then the continue statement is used to skip the remaining code in the loop iteration and move to the next iteration. This allows the program to keep asking for choices until the loop’s iteration limit is reached.
The “goto” Statement
The goto statement in the C programming language is a control flow construct that allows you to change the sequence of program execution by transferring control to a specific labelled point within your code. This labelled point is essentially a marker you place at a particular location in your program, and the goto statement directs the program to jump to that marker.
- Label Creation:
You define a label by placing an identifier followed by a colon (:) at the beginning of a line. This label serves as a reference point that the goto statement will target. - Using the goto Statement:
When you encounter a situation where you want to change the flow of your program, you can use the goto statement followed by the label you want to jump to. When the program reaches this statement, it immediately transfers control to the labelled line. - Jumping to the Labelled Point:
Once the goto statement is executed, the program jumps to the line with the corresponding label and continues executing from that point onward.
#include <stdio.h>
int main() {
int choice;
start:
printf("Enter choice: ");
scanf("%d", &choice);
switch (choice) {
case 1:
printf("Option 1 selected.\n");
goto start;
case 2:
printf("Option 2 selected.\n");
goto start;
default:
printf("Invalid option.\n");
break;
}
return 0;
}
Output: -
Enter choice: 1
Option 1 selected.Explanation:
In this program, the goto statement is used to create a loop-like behavior. The label start is placed before the input prompt, and after processing each choice, the program jumps back to the start label using goto. This effectively creates a loop that continues until the user enters an invalid option.
FQA’s
Q1: What is the switch case statement in C?
The switch case statement is a control structure in C that allows you to evaluate the value of an expression and execute different code blocks based on its value. It provides an efficient way to handle multiple conditional cases in a concise manner.
Q2: How does the switch case statement work?
The switch statement evaluates an expression and compares its value to constant values specified in the case labels. When a match is identified, the associated code block is executed. If no match is found, the code under the default label (optional) is executed.
Q3: When should I use the goto statement?
The goto statement is used to transfer the control of the program to a labeled statement. It’s often discouraged in modern programming practices due to its potential to make code harder to understand and maintain. It’s generally recommended to use structured programming constructs like loops and conditional statements instead.
Q4: How can I use the continue statement in C?
The continue statement is used within loops to immediately stop the current iteration and move to the next iteration of the loop. It’s often used to skip certain parts of a loop’s body when a specific condition is met.
Q5: Can I use goto in a switch case statement?
Yes, you can use the goto statement within a switch case block. However, using goto in this context is generally not recommended as it can make your code harder to follow and understand. It’s better to use other control structures like loops and conditional statements to achieve the desired behavior.
Q6: What are the alternatives to using goto?
Instead of using goto, you can use structured programming constructs like loops and conditional statements. For loops, while loops, and if-else statements are more readable and maintainable ways to achieve the desired flow of control in your program.
Q7: Is the continue statement the same as break?
No, the continue and break statements serve different purposes. The continue statement skip the current iteration of a loop and move to the next one. The break statement is used to immediately exit the current loop or switch case block and continue with the next part of the program.
Q8: Are there any scenarios where using goto is appropriate?
While modern programming practices generally discourage the use of goto, there are a few rare scenarios where it might be appropriate, such as implementing error handling in complex situations. However, even in these cases, alternative structured programming approaches should be considered first.
Read more about programming in c: –
Data type and Operator in C: – https://xcoode.co.in/c_programming/data-type-and-operators-in-c/
if else statement in c: – https://xcoode.co.in/c_programming/if-else-statement-in-c/
Loop’s in c: – https://xcoode.co.in/c_programming/loop-in-c/
Follow us on: –
Facebook page: – https://www.facebook.com/groups/294849166389180
Quora : – https://xcoode404.quora.com/