Introduce Java Else and give examples
In Java, the else
statement is used in conjunction with an if
statement to provide an alternative block of code that executes when the condition in the if
statement evaluates to false
. This allows for conditional execution of code, enabling different paths of execution based on certain conditions.
The basic syntax of an if-else
statement in Java is as follows:
if (condition) {
// Code to execute if condition is true
} else {
// Code to execute if condition is false
}
Here’s a simple example that checks if a number is positive or negative:
public class IfElseExample {
public static void main(String[] args) {
int number = -5;
if (number >= 0) {
System.out.println("The number is positive.");
} else {
System.out.println("The number is negative.");
}
}
}
Output:
The number is negative.
You can also use else if
to check multiple conditions:
public class IfElseIfExample {
public static void main(String[] args) {
int score = 85;
if (score >= 90) {
System.out.println("Grade: A");
} else if (score >= 80) {
System.out.println("Grade: B");
} else if (score >= 70) {
System.out.println("Grade: C");
} else {
System.out.println("Grade: D");
}
}
}
Output:
Grade: B
You can also nest if-else
statements within each other:
public class NestedIfElseExample {
public static void main(String[] args) {
int age = 20;
if (age >= 18) {
System.out.println("You are an adult.");
if (age >= 65) {
System.out.println("You are a senior citizen.");
} else {
System.out.println("You are not a senior citizen.");
}
} else {
System.out.println("You are a minor.");
}
}
}
Output:
You are an adult.
You are not a senior citizen.
The else
statement in Java is a powerful tool for controlling the flow of your program based on conditions. By using if
, else if
, and else
, you can create complex decision-making structures that allow your program to respond differently based on varying inputs or states.