PHP;"> switch (expression) { case label1: code to be executed if expression = label1; break; case label2: code to be executed if expression = label2; break; default: code to be executed if expression is different from both label1 and label2; }

PHP;"> switch($i){ case 1: echo 1; break; case 2: echo 2; break; default: echo 'others'; }

PHP;"> =90 && $score<=100: echo "优
"; break; case $score>=80 && $score<90: echo "良
"; break; case $score>=70 && $score<80: echo "中
"; break; case $score>=60 && $score<70: echo "及格
"; break; case $score>=0 && $score<60: echo "不及格
"; break; default: echo"成绩输入错误
"; } ?>

PHP;"> PHP //switch细节 //情况一：数值匹配的时候自动转换成字串 $a=1; switch($a){ case "1": echo 'hello1'; break; default: echo 'sorry none is the same!'; break; } echo '
'.'成功退出····'; echo '

---

'; //情况二：数值匹配的时候自动转换成字符 $a=1; switch($a){ case '1': echo 'hello2'; break; default: echo 'sorry none is the same!'; break; } echo '
'.'成功退出····'; echo '

---

'; //情况三：字符匹配的时候自动转换成数值 $a='1'; switch($a){ case 1: echo 'hello3'; break; default: echo 'sorry none is the same!'; break; } echo '
'.'成功退出····'; echo '

---

'; //情况四：字串匹配的时候自动转换成数值 $a="1"; switch($a){ case 1: echo 'hello4'; break; default: echo 'sorry none is the same!'; break; } echo '
'.'成功退出····'; echo '

---

'; //情况五：float也可以匹配 $a=1.1; switch($a){ case 1.1: echo 'hello5'; break; default: echo 'sorry none is the same!'; break; } echo '
'.'成功退出····'; echo '

---

'; //情况六：非0是true $a=true; switch($a){ case 1: echo 'hello6'; break; case true: echo 'hello61'; break; default: echo 'sorry none is the same!'; break; } echo '
'.'成功退出····'; echo '

---

'; //情况七：能匹配boolean $a=true; switch($a){ case true: echo 'hello7'; break; case 2: echo 'hello71'; break; default: echo 'sorry none is the same!'; break; } echo '
'.'成功退出····'; echo '

---

'; //情况八：能匹配null $a=null; switch($a){ case 2://'' "" false 0 都能进入 echo 'hello8'; break; case null: echo 'hello81'; break; default: echo 'sorry none is the same!'; break; } echo '
'.'成功退出····'; echo '

---

'; //情况九：退出顺序 $a=5; switch($a){ case 1: echo 'hello6'; break; case 2: echo '我是2号出口'; break; case 5: echo '我是5号出口'; //break; case true: echo 'hello61'; break; default: echo 'sorry none is the same!'; break; } echo '
'.'成功退出····'; echo '

---

'; //情况十：退出顺序 $a=50; switch($a){ default: echo 'sorry none is the same!'; //break; case 50: echo 'hello6'; //break; case 2: echo '我是2号出口'; break; case 5: echo '我是5号出口'; //break; case 6: echo 'hello61'; break; } echo '
'.'成功退出····'; echo '

---

'; ?>

退出···· hello2 成功退出···· hello3 成功退出···· hello4 成功退出···· hello5 成功退出···· hello6 成功退出···· hello7 成功退出···· hello81 成功退出···· 我是5号出口hello61 成功退出···· hello6我是2号出口 成功退出····