The else-if ladder is used when a program needs to check multiple conditions one after another. The program checks the first condition. If it is false, it checks the next condition, and so on. When a true condition is found, its block is executed and the remaining conditions are skipped.
An else-if ladder allows us to test multiple conditions in sequence.
if (condition1) {
// code
}
else if (condition2) {
// code
}
else if (condition3) {
// code
}
else {
// code
}A simple if-else statement provides two choices. When we have more than two possible choices, an else-if ladder is useful.
For example:
int marks = 75;
if (marks >= 90) {
std::cout << "Grade A";
}
else if (marks >= 75) {
std::cout << "Grade B";
}
else {
std::cout << "Below Grade B";
}The first condition is false, but the second condition is true, so Grade B is displayed.
if (condition1) {
// statements
}
else if (condition2) {
// statements
}
else if (condition3) {
// statements
}
else {
// default statements
}There can be multiple else-if blocks between the initial if and the final else.
int marks = 85;
if (marks >= 90) {
std::cout << "Grade A";
}
else if (marks >= 80) {
std::cout << "Grade B";
}
else if (marks >= 70) {
std::cout << "Grade C";
}
else {
std::cout << "Needs improvement";
}int age = 25;
if (age < 13) {
std::cout << "Child";
}
else if (age < 20) {
std::cout << "Teenager";
}
else if (age < 60) {
std::cout << "Adult";
}
else {
std::cout << "Senior";
}An else-if ladder can handle three possible results.
int number = 0;
if (number > 0) {
std::cout << "Positive";
}
else if (number < 0) {
std::cout << "Negative";
}
else {
std::cout << "Zero";
}#include <iostream>
int main() {
int marks;
std::cout << "Enter marks: ";
std::cin >> marks;
if (marks >= 90) {
std::cout << "Grade A";
}
else if (marks >= 75) {
std::cout << "Grade B";
}
else if (marks >= 60) {
std::cout << "Grade C";
}
else if (marks >= 40) {
std::cout << "Grade D";
}
else {
std::cout << "Fail";
}
return 0;
}The order of conditions is very important in an else-if ladder. Conditions are checked from top to bottom.
int marks = 95;
if (marks >= 90) {
std::cout << "A";
}
else if (marks >= 80) {
std::cout << "B";
}The first condition is true, so the second condition is not checked.
int marks = 85;
if (marks >= 90) {
std::cout << "A";
}
else if (marks >= 80) {
std::cout << "B";
}
else if (marks >= 70) {
std::cout << "C";
}Although 85 is also greater than 70, only B is displayed because the first true condition ends the ladder.
The final else is optional.
int age = 20;
if (age < 13) {
std::cout << "Child";
}
else if (age < 20) {
std::cout << "Teenager";
}If no condition is true, nothing is executed because there is no final else.
Relational operators are commonly used in else-if conditions.
int number = 50;
if (number > 50) {
std::cout << "Greater than 50";
}
else if (number == 50) {
std::cout << "Equal to 50";
}
else {
std::cout << "Less than 50";
}Multiple conditions can be combined using the && operator.
int age = 25;
if (age < 13) {
std::cout << "Child";
}
else if (age >= 13 && age < 20) {
std::cout << "Teenager";
}
else {
std::cout << "Adult";
}int temperature = 30;
if (temperature < 10) {
std::cout << "Cold";
}
else if (temperature < 25) {
std::cout << "Cool";
}
else if (temperature < 35) {
std::cout << "Warm";
}
else {
std::cout << "Hot";
}int salary = 30000;
if (salary < 20000) {
std::cout << "Low salary";
}
else if (salary < 50000) {
std::cout << "Medium salary";
}
else {
std::cout << "High salary";
}int number = 15;
if (number % 3 == 0 && number % 5 == 0) {
std::cout << "Divisible by both 3 and 5";
}
else if (number % 3 == 0) {
std::cout << "Divisible by 3";
}
else if (number % 5 == 0) {
std::cout << "Divisible by 5";
}
else {
std::cout << "Not divisible by 3 or 5";
}int day = 3;
if (day == 1) {
std::cout << "Monday";
}
else if (day == 2) {
std::cout << "Tuesday";
}
else if (day == 3) {
std::cout << "Wednesday";
}
else {
std::cout << "Other day";
}int month = 2;
if (month == 1) {
std::cout << "January";
}
else if (month == 2) {
std::cout << "February";
}
else if (month == 3) {
std::cout << "March";
}
else {
std::cout << "Another month";
}char grade = 'B';
if (grade == 'A') {
std::cout << "Excellent";
}
else if (grade == 'B') {
std::cout << "Very Good";
}
else if (grade == 'C') {
std::cout << "Good";
}
else {
std::cout << "Needs improvement";
}#include <iostream>
#include <string>
int main() {
std::string role = "teacher";
if (role == "admin") {
std::cout << "Admin Dashboard";
}
else if (role == "teacher") {
std::cout << "Teacher Dashboard";
}
else if (role == "student") {
std::cout << "Student Dashboard";
}
else {
std::cout << "Unknown role";
}
return 0;
}int units = 250;
if (units <= 100) {
std::cout << "Low usage";
}
else if (units <= 200) {
std::cout << "Medium usage";
}
else if (units <= 300) {
std::cout << "High usage";
}
else {
std::cout << "Very high usage";
}double amount = 6000;
if (amount >= 10000) {
std::cout << "20% discount";
}
else if (amount >= 5000) {
std::cout << "10% discount";
}
else if (amount >= 2000) {
std::cout << "5% discount";
}
else {
std::cout << "No discount";
}#include <iostream>
int main() {
int marks;
std::cout << "Enter your marks: ";
std::cin >> marks;
if (marks >= 90) {
std::cout << "Grade A";
}
else if (marks >= 75) {
std::cout << "Grade B";
}
else if (marks >= 60) {
std::cout << "Grade C";
}
else if (marks >= 40) {
std::cout << "Grade D";
}
else {
std::cout << "Fail";
}
return 0;
}An else-if ladder can also work with floating-point values.
double percentage = 82.5;
if (percentage >= 90.0) {
std::cout << "Excellent";
}
else if (percentage >= 75.0) {
std::cout << "Very Good";
}
else if (percentage >= 60.0) {
std::cout << "Good";
}
else {
std::cout << "Needs improvement";
}An else-if ladder can also contain another if statement inside one of its blocks.
int marks = 85;
if (marks >= 90) {
std::cout << "Grade A";
}
else if (marks >= 75) {
std::cout << "Grade B";
if (marks >= 85) {
std::cout << " - Very good score";
}
}
else {
std::cout << "Below Grade B";
}A common mistake is placing a broad condition before a more specific condition.
int marks = 95;
if (marks >= 40) {
std::cout << "Pass";
}
else if (marks >= 90) {
std::cout << "Grade A";
}The first condition is already true for 95, so the second condition will never be reached. More specific conditions should generally be checked first when using ranges like this.
#include <iostream>
int main() {
int marks;
std::cout << "Enter marks: ";
std::cin >> marks;
if (marks > 100 || marks < 0) {
std::cout << "Invalid marks";
}
else if (marks >= 90) {
std::cout << "Grade A";
}
else if (marks >= 75) {
std::cout << "Grade B";
}
else if (marks >= 60) {
std::cout << "Grade C";
}
else if (marks >= 40) {
std::cout << "Grade D";
}
else {
std::cout << "Fail";
}
return 0;
}This example first checks for invalid marks and then checks the grades from the highest range to the lowest.
An else-if ladder stops after finding the first true condition. Separate if statements can check every condition independently.
else-if ladder:
if (marks >= 90) {
std::cout << "A";
}
else if (marks >= 80) {
std::cout << "B";
}For mutually exclusive choices, an else-if ladder is useful because only the first matching block is executed.
if (condition1) {
// first choice
}
else if (condition2) {
// second choice
}
else {
// default choice
}| Part | Purpose |
|---|---|
if |
Checks the first condition. |
else if |
Checks another condition when previous conditions are false. |
else |
Runs when none of the previous conditions are true. |
| Order | Conditions are checked from top to bottom. |
| Execution | Only the first true block is executed. |
if (condition1) {
// statement
}
else if (condition2) {
// statement
}
else if (condition3) {
// statement
}
else {
// default statement
}Question: In an else-if ladder, what happens after the first true condition is found?