In order to match the city and state using regular expression, we use the matches method in Java. The java.lang.String.matches() method returns a boolean value which depends on the matching of the String with the regular expression.Declaration − The java.lang.String.matches() method is declared as follows −Example Live Demopublic class Example {    public static void main( String[] args ) {       System.out.println(city("Mumbai"));       System.out.println(state("Goa"));    }    // validating the city    public static boolean city( String c ) {       return c.matches( "([a - zA - Z] + |[a - zA - Z] + ... Read More

In order to catch the assertion error, we need to declare the assertion statement in the try block with the second expression being the message to be displayed and catch the assertion error in the catch block.Let us see a program on how to handle Assertion Error in Java −Examplepublic class Example {    public static void main(String[] args) throws Exception {       try {          assert args.length > 0 : "Assertion error caught!!!!";       }       catch (AssertionError e) {          System.out.println(e.getMessage());       }    } }Output

In order to handle the assertion error, we need to declare the assertion statement in the try block and catch the assertion error in the catch block.Let us see a program on how to handle Assertion Error in Java −Examplepublic class Example {    public static void main(String[] args) throws Exception {       try {          assert args.length > 0;       }       catch (AssertionError e) {          System.out.println(e.getMessage());       }    } }Output

By default, assertions are disabled in Java. In order to enable them we use the following command −java -ea Example (or) java -enableassertions ExampleHere, Example is the name of the Java file.Let us see an example for generation of an assertion error by the JVM −Example Live Demopublic class Example {    public static void main(String[] args) {       int age = 14;       assert age >= 18 : "Cannot Vote";       System.out.println("The voter's age is " + age);    } }OutputThe voter's age is 14

In order to compile assert in Java, we simply set the boolean expression as false.Let us see an example program −Example Live Demopublic class Example {    public static void main(String[] args) {       assert false;       System.out.println("Compiled and executed successfully!!!");    } }OutputCompiled and executed successfully!!!

An assertion is a statement in Java which ensures the correctness of any assumptions which have been done in the program. When an assertion is executed, it is assumed to be true. If the assertion is false, the JVM will throw an Assertion error. It finds it application primarily in the testing purposes. Assertion statements are used along with boolean expressions.Assertions in Java can be done with the help of the assert keyword. There are two ways in which an assert statement can be used.First Way −assert expression;Second Way −assert expression1 : expression2By default, assertions are disabled in Java. In ... Read More

In order to get the name of the Thread, we use the getName() method in Java. This method returns the name of the thread.Declaration − The java.lang.Thread.getName() method is declared as follows −public String getName()In order to get the identity of the Thread, we use the getId() method in Java. This method returns the identifier of the thread. The thread ID is a positive long number produced during the creation of the thread.Declaration − The java.lang.Thread.getId() method is declared as follows −public long getId()In order to get the state of the Thread, we use the getState() method in Java. This ... Read More

To format message with short length format for date in Java, we use the MessageFormat class and the Date class. The MessageFormat class gives us a way to produce concatenated messages which are not dependent on the language. The MessageFormat class extends the Serializable and Cloneable interfaces.Declaration − The java.text.MessageFormat class is declared as follows −public class MessageFormat extends FormatThe  MessageFormat.format(pattern, params) method formats the message and fills in the missing parts using the objects in the params array matching up the argument numbers and the array indices.The format method has two arguments, a pattern and an array of arguments. ... Read More

In this article, we will learn how to fill elements in a float array in Java. The Arrays.fill() method is used to assign a specified value to each element of the array. Array fill() method The Arrays.fill() method in Java sets all elements of an array to a given value, making it useful for quickly initializing or resetting arrays. The Arrays.fill() method works with various data types like int, char, double, and boolean. It makes it easy to fill arrays with a default or specific value. Syntax Arrays.fill(array, value)Arrays.fill(array, start, end, value) ... Read More

To format message with medium style format of date in Java, we use the MessageFormat class and the Date class. The MessageFormat class gives us a way to produce concatenated messages which are not dependent on the language. The MessageFormat class extends the Serializable and Cloneable interfaces.Declaration − The java.text.MessageFormat class is declared as follows −public class MessageFormat extends FormatThe  MessageFormat.format(pattern, params) method formats the message and fills in the missing parts using the objects in the params array matching up the argument numbers and the array indices.The format method has two arguments, a pattern and an array of arguments. ... Read More