Conditional statements help a program make decisions. They check whether a condition is true or false and execute different blocks of code based on the result. This allows programs to behave differently in different situations.
If Conditional Statement
The if statement checks a condition and executes a block of code only when the condition is true.
using namespace std;
int main()
{
int x = 7;
if (x > 0)
{
cout << "x is positive";
}
return 0;
}
#include <stdio.h>
int main()
{
int x = 7;
if (x > 0)
{
printf("x is positive");
}
return 0;
}
public class GFG {
public static void main(String[] args)
{
int x = 7;
if (x > 0) {
System.out.println("x is positive");
}
}
}
x = 7
if x > 0:
print("x is positive")
using System;
class GFG {
static void Main()
{
int x = 7;
if (x > 0) {
Console.WriteLine("x is positive");
}
}
}
let x = 7;
if (x > 0) {
console.log("x is positive");
}
Output
x is positive
If-Else Conditional Statement
The if-else statement checks a condition and runs one block of code if the condition is true, and another block of code if the condition is false.
Flowchart of If-Else Statement
using namespace std;
int main()
{
int x = 7;
if (x > 0)
{
cout << "x is positive";
}
else
{
cout << "x is not positive";
}
return 0;
}
#include <stdio.h>
int main()
{
int x = 7;
if (x > 0)
{
printf("x is positive");
}
else
{
printf("x is not positive");
}
return 0;
}
public class GFG {
public static void main(String[] args)
{
int x = 7;
if (x > 0) {
System.out.println("x is positive");
}
else {
System.out.println("x is not positive");
}
}
}
x = -5
if x > 0:
print("x is positive")
else:
print("x is not positive")
using System;
class GFG {
static void Main()
{
int x = 7;
if (x > 0) {
Console.WriteLine("x is positive");
}
else {
Console.WriteLine("x is not positive");
}
}
}
let x = 7;
if (x > 0) {
console.log("x is positive");
}
else {
console.log("x is not positive");
}
Output
x is positive
if-Else if Conditional Statement
The if-else if statement is used to check multiple conditions. The program evaluates each condition one by one and executes the block of code for the first condition that is true.
Flowchart of If-Else if Statement
using namespace std;
int main()
{
int x = 0;
if (x > 0)
{
cout << "x is positive";
}
else if (x < 0)
{
cout << "x is negative";
}
else
{
cout << "x is zero";
}
return 0;
}
#include <stdio.h>
int main()
{
int x = 0;
if (x > 0)
{
printf("x is positive");
}
else if (x)
{
printf("x is negative");
}
else
{
printf("x is zero");
}
return 0;
}
public class GFG {
public static void main(String[] args)
{
int x = 0;
if (x > 0) {
System.out.println("x is positive");
}
else if (x < 0) {
System.out.println("x is negative");
}
else {
System.out.println("x is zero");
}
}
}
x = 0
if x > 0:
print("x is positive")
elif x < 0:
print("x is negative")
else:
print("x is zero")
using System;
class GFG {
static void Main()
{
int x = 0;
if (x > 0) {
Console.WriteLine("x is positive");
}
else if (x < 0) {
Console.WriteLine("x is negative");
}
else {
Console.WriteLine("x is zero");
}
}
}
let x = 0;
if (x > 0) {
console.log("x is positive");
}
else if (x < 0) {
console.log("x is negative");
}
else {
console.log("x is zero");
}
Output
x is positive
Switch Conditional Statement
The switch statement checks a variable against multiple possible values. Each option is written as a case, and the program executes the matching case. A break statement is usually used to stop execution after a case runs.
Flowchart of Switch Statement
Rules of the Switch Statement
When using switch statements, there are a few important rules.
- Case values must be constant values.
- Duplicate case values are not allowed.
- A switch statement can contain multiple case blocks.
- The break statement is optional, but recommended to prevent fall-through.
- The default case is optional but useful for handling unexpected values
using namespace std;
int main()
{
int day = 2;
switch (day)
{
case 1:
cout << "Monday" << endl;
break;
case 2:
cout << "Tuesday" << endl;
break;
case 3:
cout << "Wednesday" << endl;
break;
default:
cout << "Invalid day!" << endl;
}
return 0;
}
#include <stdio.h>
int main() {
int day = 2;
switch (day) {
case 1:
printf("Monday\n");
break;
case 2:
printf("Tuesday\n");
break;
case 3:
printf("Wednesday\n");
break;
default:
printf("Invalid day!\n");
}
return 0;
}
public class GFG {
public static void main(String[] args) {
int day = 2;
switch (day) {
case 1:
System.out.println("Monday");
break;
case 2:
System.out.println("Tuesday");
break;
case 3:
System.out.println("Wednesday");
break;
default:
System.out.println("Invalid day!");
}
}
}
day = 3
match day:
case 1:
print("Monday")
case 2:
print("Tuesday")
case 3:
print("Wednesday")
case _:
print("Invalid day!")
using System;
class GFG {
static void Main() {
int day = 2;
switch (day) {
case 1:
Console.WriteLine("Monday");
break;
case 2:
Console.WriteLine("Tuesday");
break;
case 3:
Console.WriteLine("Wednesday");
break;
default:
Console.WriteLine("Invalid day!");
break;
}
}
}
let day = 2;
switch(day) {
case 1:
console.log("Monday");
break;
case 2:
console.log("Tuesday");
break;
case 3:
console.log("Wednesday");
break;
default:
console.log("Invalid day!");
}
Key Considerations for Switch Case Statements
1. Constant Expression: A switch expression must evaluate to a constant value. This can include constants or arithmetic operations.
using namespace std;
int main()
{
const int x = 10;
const int y = 5;
switch (x + y)
{
case 15:
cout << "Result is 15." << endl;
break;
case 20:
cout << "Result is 20." << endl;
break;
default:
cout << "No match found." << endl;
}
return 0;
}
#include <stdio.h>
int main()
{
const int x = 10;
const int y = 5;
switch (x + y)
{
case 15:
printf("Result is 15.\n");
break;
case 20:
printf("Result is 20.\n");
break;
default:
printf("No match found.\n");
}
return 0;
}
public class GFG {
public static void main(String[] args)
{
final int x = 10;
final int y = 5;
switch (x + y) {
case 15:
System.out.println("Result is 15.");
break;
case 20:
System.out.println("Result is 20.");
break;
default:
System.out.println("No match found.");
}
}
}
x = 10
y = 5
match x + y:
case 15:
print("Result is 15.")
case 20:
print("Result is 20.")
case _:
print("No match found.")
using System;
class Program {
static void Main()
{
int x = 10;
int y = 5;
int sum = x + y; // now sum is a variable
switch (sum) {
case 15:
Console.WriteLine("Result is 15.");
break;
case 20:
Console.WriteLine("Result is 20.");
break;
default:
Console.WriteLine("No match found.");
break;
}
}
}
const x = 10;
const y = 5;
switch (x + y) {
case 15:
console.log("Result is 15.");
break;
case 20:
console.log("Result is 20.");
break;
default:
console.log("No match found.");
}
Output
Result is 15.
2. Limited to Certain Types: Switch statements are mainly designed for int, char, or string values depending on the language.
#include <iostream>
using namespace std;
int main()
{
char grade = 'B';
switch (grade)
{
case 'A':
cout << "Excellent!" << endl;
break;
case 'B':
cout << "Good!" << endl;
break;
default:
cout << "Not specified." << endl;
}
return 0;
}
#include <stdio.h>
int main()
{
char grade = 'B';
switch (grade)
{
case 'A':
printf("Excellent!\n");
break;
case 'B':
printf("Good!\n");
break;
default:
printf("Not specified.\n");
}
return 0;
}
public class GFG {
public static void main(String[] args)
{
char grade = 'B';
switch (grade) {
case 'A':
System.out.println("Excellent!");
break;
case 'B':
System.out.println("Good!");
break;
default:
System.out.println("Not specified.");
}
}
}
grade = 'B'
match grade:
case 'A':
print("Excellent!")
case 'B':
print("Good!")
case _:
print("Not specified.")
using System;
class GFG {
static void Main()
{
char grade = 'B';
switch (grade) {
case 'A':
Console.WriteLine("Excellent!");
break;
case 'B':
Console.WriteLine("Good!");
break;
default:
Console.WriteLine("Not specified.");
break;
}
}
}
let grade = "B";
switch (grade) {
case "A":
console.log("Excellent!");
break;
case "B":
console.log("Good!");
break;
default:
console.log("Not specified.");
}
Output
Good!
Ternary Expression Conditional Statement
The ternary operator is a short way to write an if-else statement. It evaluates a condition and returns one value if the condition is true, and another value if the condition is false.
- It is called a ternary operator because each ternary expression uses three parts.
- Multiple ternary expressions can also be nested to check more conditions.
Flowchart of Ternary Condition
using namespace std;
int main()
{
int x = 10;
cout << (x > 0 ? "x is positive" : "x is not positive");
return 0;
}
#include <stdio.h>
int main()
{
int x = 10;
printf(x > 0 ? "x is positive" : "x is not positive");
return 0;
}
import java.util.Scanner;
public class GFG {
public static void main(String[] args)
{
int x = 10;
System.out.println(x > 0 ? "x is positive"
: "x is not positive");
}
}
x = 10
print("x is positive" if x > 0 else "x is not positive")
using System;
class GFG {
static void Main()
{
int x = 10;
Console.WriteLine(x > 0 ? "x is positive"
: "x is not positive");
}
}
let x = 10;
console.log(x > 0 ? "x is positive" : "x is not positive");
Output
x is positive
Nested Ternary Condition: A nested ternary condition is a ternary operator placed inside another ternary operator. It is used when you need to check multiple conditions in a single line. The inner ternary executes only if required by the outer condition.
Flowchart of Nested Ternary Condition
using namespace std;
int main()
{
int x = 0;
cout << (x > 0 ? "x is positive" : (x < 0 ? "x is not positive" : "x is zero"));
return 0;
}
#include <stdio.h>
int main()
{
int x = 0;
printf(x > 0 ? "x is positive" : (x < 0 ? "x is not positive" : "x is zero"));
return 0;
}
import java.util.Scanner;
public class GFG {
public static void main(String[] args)
{
int x = 0;
System.out.println(
x > 0 ? "x is positive"
: (x < 0 ? "x is not positive"
: "x is zero"));
}
}
x = 0
print("x is positive" if x > 0 else (
"x is not positive" if x < 0 else "x is zero"))
using System;
class GFG {
static void Main()
{
int x = 0;
Console.WriteLine(x > 0
? "x is positive"
: (x < 0 ? "x is not positive"
: "x is zero"));
}
}
let x = 0;
console.log(
x > 0 ? "x is positive"
: (x < 0 ? "x is not positive" : "x is zero"));
Output
x is zero