Advance-Java User Input (Scanner class) in Java #27

#java #Corejava #scannerclass #inputinjava

@King

Java Scanner. Scanner class in Java is found in the java.util package. Java provides various ways to read input from the keyboard, the java.util.Scanner class is one of them. The Java Scanner class breaks the input into tokens using a delimiter which is whitespace by default.

Scanner is a class in java.util package used for obtaining the input of the primitive types like int, double, etc. and strings. It is the easiest way to read input in a Java program, though not very efficient if you want an input method for scenarios where time is a constraint like in competitive programming.

To create an object of Scanner class, we usually pass the predefined object System.in, which represents the standard input stream. We may pass an object of class File if we want to read input from a file.
To read numerical values of a certain data type XYZ, the function to use is nextXYZ(). For example, to read a value of type short, we can use nextShort()
To read strings, we use nextLine().
To read a single character, we use next().charAt(0). next() function returns the next token/word in the input as a string and charAt(0) function returns the first character in that string.

To use the Scanner class, create an object of the class and use any of the available methods found in the Scanner class documentation. In our example, we will use the nextLine () method, which is used to read Strings: If you don't know what a package is, read our Java Packages Tutorial.

To create an object of Scanner class, we usually pass the predefined object System.in, …
To read numerical values of a certain data type XYZ, the function to use is nextXYZ (). For …
To read strings, we use nextLine ().