java source code reading System

Type 1 Signatures and Notes

public final class System

The System class contains some useful class properties and methods. This class cannot be instantiated.

 

2 standard input and output streams

public final static InputStream in = null;

public final static PrintStream out = null;

Standard input and output streams are initialized in the initializeSystemClass method.

(1) Console input and output

1 Scanner in = new Scanner(System.in);  
2 System.out.println(in.nextLine());  

When the code runs to line 1, it will wait for the user to input in the console, and then pass the println method of out.

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