1 <!DOCTYPE html> 2 <html lang="en"> 3 <head> 4 <meta charset="UTF-8" /> 5 <title>Document</title> 6 </head> 7 <body> 8 <form action="" method="POST" > 9 10 <?php 11 12 $a1=(isset($_POST[‘a1‘])) ? $_POST[‘a1‘] : ‘‘; 13 $a2=(isset($_POST[‘a2‘])) ? $_POST[‘a2‘] : ‘‘; 14 $a3=(isset($_POST[‘a3‘])) ? $_POST[‘a3‘] : ‘‘; 15 16 17 if(isset($_POST[‘add‘]) ? ‘add‘ : ‘‘){ 18 $a3 = ($a1 && $a2)? ($a1 + $a2): ‘NaN‘; 19 } 20 if(isset($_POST[‘sub‘]) ? ‘-‘ : ‘‘){ 21 $a3 = ($a1 && $a2)? ($a1 - $a2): ‘NaN‘; 22 } 23 if(isset($_POST[‘mun‘]) ? ‘mun‘: ‘‘){ 24 $a3 = ($a1===0 && $a2===0) ? ($a1 * $a2): ‘NaN‘; 25 } 26 if(isset($_POST[‘div‘]) ? ‘/‘ : ‘‘){ 27 $a3 = ($a1 && $a2) ? ($a1 / $a2) : ‘NaN‘; 28 } 29 30 ?> 31 32 数值1：<input type="number" name="a1" value=‘<?php echo $a1; ?>‘/> 33 数值2：<input type="number" name="a2" value=‘<?php echo $a2; ?>‘/> 34 <input type="submit" value="+" name="add" /> 35 <input type="submit" value="-" name="sub" /> 36 <input type="submit" value="*" name="mun" /> 37 <input type="submit" value="/" name="div" /> 38 <input disabled=‘disabled‘ value=‘<?php echo $a3; ?>‘> 39 </form> 40 41 </body> 42 </html>
原文：https://www.cnblogs.com/vaso-me/p/11223630.html