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While a superclass method throws an exception while overriding it you need to follow the certain rules.The sub class method Should throw Same exception or, sub type −It should not throw an exception of super type −You may leave the method in sub class Without throwing any exceptionAccording to the 3rd rule, if the super-class method throws certain exception, you can override it without throwing any exception.ExampleIn the following example the sampleMethod() method of the super-class throws FileNotFoundException exception and, the sampleMethod() method does not throw any exception at all. Still this program gets compiled and executed without any errors.import ... Read More
From Java 1.5 Scanner class was introduced. This class accepts a File, InputStream, Path and, String objects, reads all the primitive data types and Strings (from the given source) token by token using regular expressions.To read various datatypes from the source using the nextXXX() methods provided by this class namely, nextInt(), nextShort(), nextFloat(), nextLong(), nextBigDecimal(), nextBigInteger(), nextLong(), nextShort(), nextDouble(), nextByte(), nextFloat(), next().Whenever you take inputs from the user using a Scanner class. If the inputs passed doesn’t match the method or an InputMisMatchException is thrown. For example, if you reading an integer data using the nextInt() method and the value ... Read More
Since Java 7 try-with resources was introduced. In this we declare one or more resources in the try block and these will be closed automatically after the use. (at the end of the try block)The resources we declare in the try block should extend the java.lang.AutoCloseable class.ExampleFollowing program demonstrates the try-with-resources in Java.import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; public class FileCopying { public static void main(String[] args) { try(FileInputStream inS = new FileInputStream(new File("E:\Test\sample.txt")); FileOutputStream outS = new FileOutputStream(new File("E:\Test\duplicate.txt"))){ byte[] buffer = new byte[1024]; ... Read More
An exception is an issue (run time error) occurred during the execution of a program. When an exception occurred the program gets terminated abruptly and, the code past the line that generated the exception never gets executed.There are two types of exceptions in Java.Unchecked Exception − An unchecked exception is the one which occurs at the time of execution. These are also called as Runtime Exceptions. These include programming bugs, such as logic errors or improper use of an API. Runtime exceptions are ignored at the time of compilation.Checked Exception − A checked exception is an exception that occurs at ... Read More
In Java you can declare three types of variables namely, instance variables, static variables and, local variables.Local variables − Variables defined inside methods, constructors or blocks are called local variables. The variable will be declared and initialized within the method and the variable will be destroyed when the method has completed.Class (static) variables − Class variables are variables declared within a class, outside any method, with the static keyword.Static methods in try-blockIn the same way, static variables belong to the class and can be accessed anywhere within the class, which contradicts with the definition of the local variable. Therefore, declaring ... Read More
Float method is part of python standard library which converts a number or a string containing numbers to a float data type. There are following rules when a string is considered to be valid for converting it to a float.The string must have only numbers in it.Mathematical operators between the numbers can also be used.The string can represent NaN or infThe white spaces at the beginning and end are always ignored.ExampleThe below program indicates how different values are returned when float function is applied.n = 89 print(type(n)) f = float(n) print(type(f)) print("input", 7, " with float function becomes ", float(7)) ... Read More
Mean, Median and Mode are very frequently used statistical functions in data analysis. Though there are some python libraries.Finding MeanMean of a list of numbers is also called average of the numbers. It is found by taking the sum of all the numbers and dividing it with the count of numbers. In the below example we apply the sum() function to get the sum of the numbers and th elen() function to get the count of numbers.Examplenum_list = [21, 11, 19, 3, 11, 5] # FInd sum of the numbers num_sum = sum(num_list) #divide the sum with length of the ... Read More
If there is a need to find 10 most frequent words in a data set, python can help us find it using the collections module. The collections module has a counter class which gives the count of the words after we supply a list of words to it. We also use the most_common method to find out the number of such words as needed by the program input.ExamplesIn the below example we take a paragraph, and then first create a list of words applying split(). We will then apply the counter() to find the count of all the words. Finally ... Read More
A list is a collection data type in Python. The elements in a list are change able and there is no specific order associated with the elements. In this article we will see how to find the length of a list in Python. Which means we have to get the count of number of elements present in the list irrespective of whether they are duplicate or not.ExamplesIn the below example we take a list named as "days". We first find the length of the list using len() function. And then we add few more elements and check the length again ... Read More
String is a python which is a series of Unicode characters. Once declared it is not changeable. In this article we'll see what are the different ways to find the length of a string.Using the len()This is the most straight forward way. Here we use a library function named len(). The string is passed as parameter to the function and we get a count of characters in the screen.Examplesstr ="Tutorials" print("Length of the String is:", len(str))OutputRunning the above code gives us the following result −Length of the String is: 9Using SlicingWe can use the string slicing approach to count the ... Read More