java - What does Scanner input = new Scanner(System.in) actually mean? -

scanner input = new scanner(system.in); 

could give me detailed explanation on code above doing step step? don't understand how works , how links me later being able statement:

int = input.nextint() 

alright, let's elaborate simplified explanation scanner class.

it standard oracle class can use calling import java.util.scanner.

so let's make basic example of class:

class scanner{    inputstream source;     scanner(inputstream src){        this.source = src;    }     int nextint(){        int nextinteger;        //scans next token of input int source.        return nextinteger;    } } 

now when call scanner input = new scanner(system.in); make new object of scanner class (so make new "scanner") , store in variable input. @ same time calling (so called) constructor of class, parameter system.in. means going read standard input stream of program.

now when calling input.nextint(); execute method object created (also documented). see, method returns integer, if want use integer, have assign call variable do:

int = input.nextint();