Interactive Programs with Scanner
Explore how to make Java programs interactive by using the Scanner class to read console input. Understand how to handle text, numeric input, and the common newline issue. Learn to combine input handling with loops and switch statements to create user-driven program flow.
Up until now, our programs have relied on hard-coded values defined directly in the source code. While this works for learning syntax, real-world software needs to be dynamic. It must respond to users, process new data, and behave differently based on external input.
To bridge the gap between our code and the user, we use the Scanner class, which allows us to read input directly from the console during execution. This capability transforms static scripts into interactive tools.
The Scanner class and text input
Java provides the java.util.Scanner class to read text and numbers from various input sources, including files and the command line. To read from the console, we connect the scanner to System.in, which represents the standard input stream (the keyboard). ...