Java If Else

Programs become useful the moment they can make decisions. Java's if...else statements let your code choose between different paths depending on whether a condition is true or false. In this lesson you will learn the four conditional keywords, how to combine them, and the compact shortcut Java gives you for simple choices.

Making decisions with conditions

A condition is any expression that evaluates to a boolean, meaning it results in either true or false. Java gives you four building blocks to react to those conditions. You use if to run a block only when something is true, else to provide a fallback, else if to test extra possibilities, and you can nest these to describe more detailed logic.

  • if - runs a block of code when its condition is true.
  • else - runs a block when the if condition (and any else if conditions) turned out to be false.
  • else if - tests a new condition when the previous one was false.
  • The ternary operator ( ? : ) - a one-line shortcut that picks between two values.

The if statement

The simplest form is a single if. You place a boolean condition in parentheses, and the code inside the curly braces runs only when that condition is true. If it is false, Java skips the block entirely and moves on.

A basic if statement

public class Main {
  public static void main(String[] args) {
    int temperature = 32;

    if (temperature > 30) {
      System.out.println("It is a hot day, stay hydrated.");
    }

    System.out.println("Program finished.");
  }
}
// Output:
// It is a hot day, stay hydrated.
// Program finished.

Adding else and else if

Most real decisions need more than one branch. Add an else to describe what should happen when the condition is false, and chain else if branches in between to test additional conditions in order. Java checks each condition from top to bottom and runs the first block whose condition is true, then skips the rest.

Grading with else if

public class Main {
  public static void main(String[] args) {
    int score = 78;

    if (score >= 90) {
      System.out.println("Grade: A");
    } else if (score >= 75) {
      System.out.println("Grade: B");
    } else if (score >= 60) {
      System.out.println("Grade: C");
    } else {
      System.out.println("Grade: F");
    }
  }
}
// Output:
// Grade: B
Note: Order matters in an else if chain. Because Java stops at the first true condition, always list your tighter or higher conditions first. If the score example checked score >= 60 before score >= 90, every passing student would be labelled a C.

The ternary shortcut

When you only need to choose between two values based on one condition, the ternary operator keeps things short. It reads as: condition ? valueIfTrue : valueIfFalse. It is an expression, so it produces a value you can store in a variable or print directly.

Choosing a value with the ternary operator

public class Main {
  public static void main(String[] args) {
    int age = 20;
    String access = (age >= 18) ? "Allowed" : "Denied";
    System.out.println(access);
  }
}
// Output:
// Allowed
KeywordPurposeRuns when
ifTest a conditionCondition is true
else ifTest another conditionAll earlier conditions were false and this one is true
elseProvide a fallbackEvery previous condition was false
? :Pick one of two values inlineUsed as a compact expression
Note: Always compare booleans directly instead of writing them out. Prefer if (isReady) over if (isReady == true) - they behave the same, but the shorter form is cleaner and avoids a common typo where == is accidentally written as a single =.

Exercise: Java If...Else

What happens if an if statement's condition is false and there is no else branch?

Keep Going

Java Interview QuestionsPractice real questions asked for JavaJava Developer SalarySee what Java Developer roles pay in the marketAuto Apply for JobsApply to open roles related to Java and tweak your resume