本文介绍php中的switch语句的用法,它跟其他语句中的switch用法差不多的,但注意有有一个break语句。
PHP中switch语句的标准语法:
1 2 3 4 5 6 7 8 9 10 11 12 | 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;
}
|
Salin selepas log masuk
举例:
1 2 3 4 5 6 7 8 9 10 | switch ( $i ){
case 1:
echo 1;
break ;
case 2:
echo 2;
break ;
default :
echo 'others' ;
}
|
Salin selepas log masuk
也可以使用switch来判断一个取值范围,或者说是在case中自定义条件。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 | <?php
header( "content-type:text/html;charset=utf8" );
$score =50;
switch ( $score )
{
case $score >=90 && $score <=100:
echo "优<br>" ;
break ;
case $score >=80 && $score <90:
echo "良<br>" ;
break ;
case $score >=70 && $score <80:
echo "中<br>" ;
break ;
case $score >=60 && $score <70:
echo "及格<br>" ;
break ;
case $score >=0 && $score <60:
echo "不及格<br>" ;
break ;
default :
echo "成绩输入错误<br>" ;
}
?>
|
Salin selepas log masuk
简单示例
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 | <?php
$a =1;
switch ( $a ){
case "1" :
echo 'hello1' ;
break ;
default :
echo 'sorry none is the same!' ;
break ;
}
echo '<br/>' . '成功退出····' ;
echo '<hr/>' ;
$a =1;
switch ( $a ){
case '1' :
echo 'hello2' ;
break ;
default :
echo 'sorry none is the same!' ;
break ;
}
echo '<br/>' . '成功退出····' ;
echo '<hr/>' ;
$a = '1' ;
switch ( $a ){
case 1:
echo 'hello3' ;
break ;
default :
echo 'sorry none is the same!' ;
break ;
}
echo '<br/>' . '成功退出····' ;
echo '<hr/>' ;
$a = "1" ;
switch ( $a ){
case 1:
echo 'hello4' ;
break ;
default :
echo 'sorry none is the same!' ;
break ;
}
echo '<br/>' . '成功退出····' ;
echo '<hr/>' ;
$a =1.1;
switch ( $a ){
case 1.1:
echo 'hello5' ;
break ;
default :
echo 'sorry none is the same!' ;
break ;
}
echo '<br/>' . '成功退出····' ;
echo '<hr/>' ;
$a =true;
switch ( $a ){
case 1:
echo 'hello6' ;
break ;
case true:
echo 'hello61' ;
break ;
default :
echo 'sorry none is the same!' ;
break ;
}
echo '<br/>' . '成功退出····' ;
echo '<hr/>' ;
$a =true;
switch ( $a ){
case true:
echo 'hello7' ;
break ;
case 2:
echo 'hello71' ;
break ;
default :
echo 'sorry none is the same!' ;
break ;
}
echo '<br/>' . '成功退出····' ;
echo '<hr/>' ;
$a =null;
switch ( $a ){
case 2:
echo 'hello8' ;
break ;
case null:
echo 'hello81' ;
break ;
default :
echo 'sorry none is the same!' ;
break ;
}
echo '<br/>' . '成功退出····' ;
echo '<hr/>' ;
$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' ;
case true:
echo 'hello61' ;
break ;
default :
echo 'sorry none is the same!' ;
break ;
}
echo '<br/>' . '成功退出····' ;
echo '<hr/>' ;
$a =50;
switch ( $a ){
default :
echo 'sorry none is the same!' ;
case 50:
echo 'hello6' ;
case 2:
echo '我是2号出口' ;
break ;
case 5:
echo '我是5号出口' ;
case 6:
echo 'hello61' ;
break ;
}
echo '<br/>' . '成功退出····' ;
echo '<hr/>' ;
?>
|
Salin selepas log masuk
运行结果
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 | hello1
成功退出····
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····
|
Salin selepas log masuk