How do you check if an object is a character in Java?

You can use contains(), indexOf() and lastIndexOf() method to check if one String contains another String in Java or not. If a String contains another String then it’s known as a substring. The indexOf() method accepts a String and returns the starting position of the string if it exists, otherwise, it will return -1.

An object of type Character contains a single field whose type is char. We can check whether the given character in a string is a number/letter by using isDigit() method of Character class . The isDigit() method is a static method and determines if the specified character is a digit.

You can check object type in Java by using the instanceof keyword . Determining object type is important if you’re processing a collection such as an array that contains more than one type of object. For example, you might have an array with string and integer representations of numbers.

Strings, which are widely used in Java programming, are a sequence of characters. In the Java programming language, strings are objects . The Java platform provides the String class to create and manipulate strings.