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Java Java Objects Harnessing the Power of Objects Handling Exceptions

Evanstar War
PLUS
Evanstar War
Courses Plus Student 536 Points

how to us IllegalArgumentException in java

why am i getting syntax error? anyone please help

Example.java
class Example {

  public static void main(String[] args) {
    GoKart kart = new GoKart("purple");
    if (kart.isBatteryEmpty()) {
      System.out.println("The battery is empty");
    }
    try{kart.drive(42);
       }
    catch(IllegalArgumentException iae){
    System.out.println("the message is %s",iae.getMessage());
    }
  }

}
GoKart.java
class GoKart {
  public static final int MAX_BARS = 8;
  private int barCount;
  private String color;
  private int lapsDriven;

  public GoKart(String color) {
    this.color = color;
  }

  public String getColor() {
    return color;
  }

  public void charge() {
    barCount = MAX_BARS;
  }

  public boolean isBatteryEmpty() {
    return barCount == 0;
  }

  public boolean isFullyCharged() {
    return MAX_BARS == barCount;
  }

  public void drive() {
    drive(1);
  }

  public void drive(int laps) {
    if (laps > barCount) {
      throw new IllegalArgumentException("Not enough battery remains");
    }
    lapsDriven += laps;
    barCount -= laps;
  }

}

2 Answers

andren
andren
28,538 Points

The error comes from the fact that you are using a formatted string (a string with placeholders like %s), but printing it out using println (print line). Which is a method which does not support formatted strings.

To print formatted string you have to use printf (print formatted) instead. Like this:

class Example {

  public static void main(String[] args) {
    GoKart kart = new GoKart("purple");
    if (kart.isBatteryEmpty()) {
      System.out.println("The battery is empty");
    }
    try{
        kart.drive(42);
    }
    catch(IllegalArgumentException iae){
        System.out.printf("the message is %s",iae.getMessage()); // Replaced println with printf
    }
  }

}
Evanstar War
PLUS
Evanstar War
Courses Plus Student 536 Points

Thank You so much for your kind help.much appreciated