位元左移運算 4<<2
- 4 換為二進制: 100
- 向左移2位即: 10000
- 也就是: 16
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| <?php define( "TIYU", 1<<1 ); define( "CHANGGE", 1<<2 ); define( "MEISHU", 1<<3 ); define( "YUEDU", 1<<4 ); $A = 2 | 8; $B = 4 | 8; $C = 2 | 4 | 16;
function aihao( $name ){ if( $name & TIYU ) echo "體育<br>"; if( $name & CHANGGE ) echo "唱歌<br>"; if( $name & MEISHU ) echo "美術<br>"; if( $name & YUEDU ) echo "閱讀<br>"; } echo '客戶A的愛好有:<br>'; aihao( $A ); echo '客戶B的愛好有:<br>'; aihao( $B ); echo '客戶C的愛好有:<br>'; aihao( $C ); ?>
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參考: http://bbs.chinaunix.net/viewthread.php?tid=1707965