Scanner-扫描器

//java.util.Scanner包是JDK自带的
import java.util.Scanner;

class ScannerDemo{

public static void main(String []args){

    //创建对象Scanner
    Scanner sc = new Scanner(System.in);
    //扫描器对象，获得我们从键盘输入的int值，sc调用nextInt()时候JVM就会等着我们输入
    int a = sc.nextInt();
    System.out.println("a的变量值"+a);
    int b = sc.nextInt();
    System.out.println("b的变量值"+b);
    int result = sum(a,b);
    System.out.println("a+b的和"+result);
}
public static int sum(int a,int b){
    return a + b;
}

}