Using assertTrue(boolean) and assertFalse(boolean) method in junit


In this JUnit Tutorial in java we will learn how to use assertTrue(boolean) and assertFalse(boolean) method in junit java.

Use assertTrue(boolean) and assertFalse(boolean) method in java junit >

assertTrue(boolean) - Method tests whether a value returned is true.
assertFalse(boolean) -  Method tests whether a value returned is false


import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;
public class AssertionsTrueFalseExample {
   public static void main(String args[]) {
      String str1 = new String("ab");
      String str2 = new String("ab");
     
      assertTrue(str1.equals(str2));
      System.out.println("after assertTrue");
      assertFalse(!str1.equals(str2));
      System.out.println("after assertFalse");
   }
}
/*OUTPUT
after assertTrue
after assertFalse
*/

Jar used in above program > junit-4.8.2.jar



Example program where assertFalse(boolean) method throws  java.lang.AssertionError in java junit >
import static org.junit.Assert.assertFalse;
public class AssertionsFalseExceptionExample {
   public static void main(String args[]) {
      String str1 = new String("ab");
      String str2 = new String("ab");
      assertFalse(str1.equals(str2));
      System.out.println("after assertFalse");
   }
}
/*OUTPUT
Exception in thread "main" java.lang.AssertionError:
   at org.junit.Assert.fail(Assert.java:91)
   at org.junit.Assert.assertTrue(Assert.java:43)
   at org.junit.Assert.assertFalse(Assert.java:68)
   at org.junit.Assert.assertFalse(Assert.java:79)
   at AssertionsFalseExceptionExample.main(AssertionsFalseExceptionExample.java:8)
*/




Example program where assertTrue(boolean) method throws  java.lang.AssertionError in java junit >
import static org.junit.Assert.assertTrue;
public class AssertionsTrueExceptionExample {
   public static void main(String args[]) {
      String str1 = new String("ab");
      String str2 = new String("xy");
     
      assertTrue(str1.equals(str2));
      System.out.println("after assertTrue");
   }
}
/*OUTPUT
Exception in thread "main" java.lang.AssertionError:
   at org.junit.Assert.fail(Assert.java:91)
   at org.junit.Assert.assertTrue(Assert.java:43)
   at org.junit.Assert.assertTrue(Assert.java:54)
   at AssertionsTrueExceptionExample.main(AssertionsTrueExceptionExample.java:8)
*/


So in this JUnit Tutorial in java we learned how to use assertTrue(boolean) and assertFalse(boolean) method in junit java.

Labels: Core Java JUNIT
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