The
if-else statement is a fundamental control structure in Java that extends the functionality of the basic if statement. It allows developers to create programs that make binary decisions by executing one block of code if a condition is true, and an alternative block of code if the condition is false. This construct is vital for creating branching logic within a program, enabling it to adapt its behavior based on varying conditions.
The syntax of the if-else statement is as follows:
if else statement
public class Main{
public static void main(String[] args) {
if (condition) {
// Code to execute if the condition is true
} else {
// Code to execute if the condition is false
}
}
}
Here's a breakdown of how the if-else statement works:
The if keyword is followed by a condition within parentheses. If the condition evaluates to true, the code block within the first set of curly braces is executed.
If the condition is false, the program moves to the else block. The else keyword is followed by a code block enclosed in another set of curly braces. The code within this block is executed when the condition is false.
The if-else statement ensures that only one of the two code blocks is executed, depending on the condition's outcome.
Here's an example that demonstrates the usage of the if-else statement:
If else - Java basic example
public class Main{
public static void main(String[] args) {
int age = 20;
if (age >= 18) {
System.out.println("You are eligible to vote.");
} else {
System.out.println("You are not eligible to vote.");
}
}
}
Output
You are eligible to vote.
In this example, if the age is greater than or equal to 18, the program prints "You are eligible to vote." to the console. If the age is less than 18, it prints "You are not eligible to vote." This binary decision-making based on the age condition is crucial for implementing various scenarios in a program.
boolean and if else example in java
public class Main{
public static void main(String[] args) {
boolean isLoggedIn = false;
if (isLoggedIn) {
System.out.println("You are logged in.");
} else {
System.out.println("You are not logged in.");
}
}
}
Output
You are not logged in.
Developers can expand the if-else construct further by using multiple else if clauses to handle additional conditions and possible outcomes. This allows for more complex decision-making and branching logic within a program.
In summary, the if-else statement is an essential tool in Java programming for creating dynamic and responsive applications. It allows programs to choose between two distinct paths based on the evaluation of a condition, enhancing the program's ability to handle different scenarios and user interactions.
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