PHP逻辑运算符范例

试试下面的例子就明白了逻辑运算符。复制并粘贴下面的内容到test.php文件，并将PHP程序保存在PHP服务器的文档根目录，使用浏览器浏览。

<html>
<head><title>PHP逻辑运算符范例</title><head>
<body>
<?php
    $a = 42;
    $b = 0;
    
    if( $a && $b ){
       echo "TEST1 : Both a and b are true<br/>";
    }else{
       echo "TEST1 : Either a or b is false<br/>";
    }
    if( $a and $b ){
       echo "TEST2 : Both a and b are true<br/>";
    }else{
       echo "TEST2 : Either a or b is false<br/>";
    }
    if( $a || $b ){
       echo "TEST3 : Either a or b is true<br/>";
    }else{
       echo "TEST3 : Both a and b are false<br/>";
    }
    if( $a or $b ){
       echo "TEST4 : Either a or b is true<br/>";
    }else{
       echo "TEST4 : Both a and b are false<br/>";
    }
    $a = 10;
    $b = 20;
    if( $a ){
       echo "TEST5 : a is true <br/>";
    }else{
       echo "TEST5 : a  is false<br/>";
    }
    if( $b ){
       echo "TEST6 : b is true <br/>";
    }else{
       echo "TEST6 : b  is false<br/>";
    }
    if( !$a ){
       echo "TEST7 : a is true <br/>";
    }else{
       echo "TEST7 : a  is false<br/>";
    }
    if( !$b ){
       echo "TEST8 : b is true <br/>";
    }else{
       echo "TEST8 : b  is false<br/>";
    }
?>
</body>
</html>

这将产生以下结果

TEST1 : Either a or b is false
TEST2 : Either a or b is false
TEST3 : Either a or b is true
TEST4 : Either a or b is true
TEST5 : a is true
TEST6 : b is true
TEST7 : a is false
TEST8 : b is false