5-1 if else ifelse 邏輯判斷語句 範例

1. 5_1.php

   <?php
   echo "<meta charset='utf-8'>";
   $a=5;
   $b=15;
   echo "\$a={$a}"."<br>";
   echo "\$b={$b}"."<br>";
   
   if($b>$a)echo '$b>$a';
   

    

2. 5_2.php

   <?php
   echo "<meta charset='utf-8'>";
   $a=25;
   $b=15;
   echo "\$a={$a}"."<br>";
   echo "\$b={$b}"."<br>";
   
   if($b>$a){
     echo '$b>$a';
   }else{
   
     echo '$a>$b';
   }
   

    

3. 5_3.php

   <?php
   echo "<meta charset='utf-8'>";
   $a=15;
   $b=15;
   echo "\$a={$a}"."<br>";
   echo "\$b={$b}"."<br>";
   
   if($b>$a){
     echo '$b > $a';
   }elseif($b<$a){
     echo '$b < $a';
   }else{
     echo '$b = $a';
   }
   

    

4. 5_4.php

   <?php
   echo "<meta charset='utf-8'>";
   $a=15;
   $b=25;
   echo "\$a={$a}"."<br>";
   echo "\$b={$b}"."<br>";
   
   $msg=($a >= $b)?'$a >= $b':'$a < $b';
   echo $msg;