java web 01 : scanner、字面值

 

//控制台输入
Scanner sc = new Scanner(System.in);
String r2 = sc.nextLine();


//控制台输出拼接
System.out.println( "圆的面积  = "+area);


//整数字面值类型为int
long a = 9999999999L;
//浮点数为double
double b = 3.1415926536d;


//八进制用0开始