Class Scanner
java.lang.Object
java.util.Scanner
All Implemented Interfaces:
Closeable, AutoCloseable, Iterator
其他不说，实现了Iterator接口
boolean hasNext()
Returns true if the iteration has more elements.
E next()
Returns the next element in the iteration.
Scanner scan = new Scanner(System.in);
String name = scan.nextLine();//回车结束输入，计入空格，是一行输入
int age = scan.nextInt();//空格结束，键盘键入有效数字开始，
//如果键入 abc（非数字字符会报错）所以有 hasNextInt();
String name = scan.next(); //输入一行如果以空格间隔，只会取到空格之前的字符，后面并不会取到。
实列：输入数字以0结束
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import java.util.Scanner;
Scanner scan = new Scanner(System.in);
String str = "";
int i = 1;
do{
i = scan.nextInt();
str += i;
}while( i != 0);
System.out.println(str);
输入两个数 n和b
import java.util.Scanner;
Scanner scan = new Scanner(System.in);
int n = 0 ;
int b = 0;
n = scan.nextInt();
b = scan.nextInt();
scan.close();
System.out.println(n +b);
