JAVA练习题

猜数字游戏。存取 5 个随机的 1~20 之间的数据

public class Test2 {

public static void main ( String [] args ) {

int [] arr = new int [ 5 ];

for ( int i = 0 ; i < arr . length ; i ++ ) {

int tmp = ( int ) ( Math . random () * 20 + 1 );

if ( exists ( arr , tmp )) {

i -- ;

} else {

arr [ i ] = tmp ;

}

}

System . out . println ( Arrays . toString ( arr ));

int target = - 1 ;

Scanner sc = new Scanner ( System . in );

while ( true ) {

System . out . println ( " 请输入所猜想的数值 " );

target = sc . nextInt ();

boolean bb = exists ( arr , target );

if ( bb ) {

System . out . println ( " 猜对了 !" );

break ;

} else {

System . out . println ( " 请继续努力 " );

}

}

sc . close ();

}

public static boolean exists ( int [] arr , int target ) {

if ( target < 1 || target > 20 )

return false ;

boolean res = false ;

for ( int tmp : arr ) {

if ( tmp == target ) {

res = true ;

break ;

}

}

return res ;

}

}