If–Else

If-else statements in Java allow you to test multiple conditions and execute different code blocks based on which condition is true.

Basic Syntax

if (condition1) {
  // Code executed if condition1 is true
} else if (condition2) {
  // Code executed if condition1 is false and condition2 is true
} else {
  // Code executed if all conditions are false
}

Basic If-Else

int score = 85;
char grade;

if (score >= 90) {
  grade = 'A';
} else if (score >= 80) {
  grade = 'B';
} else {
  grade = 'C';
}

System.out.println("Grade: " + grade);  // Output: Grade: B

Nested If-Else-If

You can nest if-else-if statements inside other if-else-if statements:

int age = 25;
boolean hasLicense = true;

if (age >= 18) {
  if (hasLicense) {
    System.out.println("You can drive alone.");
  } else {
    System.out.println("You need to get a license first.");
  }
} else if (age >= 16) {
  System.out.println("You can drive with an adult supervisor.");
} else {
  System.out.println("You are too young to drive.");
}

Logical Operators in Conditions

You can combine multiple conditions using logical operators:

int temperature = 25;
boolean isRaining = false;

if (temperature > 30 && !isRaining) {
  System.out.println("Great day for the beach!");
} else if (temperature > 20 || !isRaining) {
  System.out.println("Good day for outdoor activities.");
} else {
  System.out.println("Better stay indoors today.");
}