[請益] 三角函數 輸入正負數(整數跟小數)結果對 輸入0卻怪怪的

看板PHP作者 (123 team)時間8年前 (2016/05/19 14:26), 8年前編輯推噓1(1011)
留言12則, 8人參與, 最新討論串1/1
sincostan.php 程式碼如下: <!doctype html> <html> <head> <style> .press { width:162px; } .error { color:#F00; } </style> <meta charset="utf-8"> <title>三角函數</title> </head> <body> <?php $scaleErr=""; settype($scale,"double"); //scale變成double型態 if ($_SERVER["REQUEST_METHOD"] == "POST") { if (empty($_POST["scale"])) { $scaleErr = "忘了寫倍數了"; } else { $scale=test_input($_POST["scale"]); $scale=$scale*pi(); //倍數可以是小數或整數 } } function test_input($data) { if(!is_string($data)) $data='scale'; $data = trim($data); $data = stripslashes($data); $data = htmlspecialchars($data); return $data; } ?> <form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>"> 請輸入倍數:<input type="text" name="scale" class="press"> <span class="error">* <?php echo $scaleErr;?></span> <br><br><input type="submit" name="submit" value="送出"><br> </form> <?php if($scale!=0){ echo "<br>"; echo "sin(".$scale.")=".sin($scale)."<br>"; echo "cos(".$scale.")=".cos($scale)."<br>"; echo "tan(".$scale.")=".tan($scale)."<br>"; echo "cot(".$scale.")=".(1/tan($scale))."<br>"; echo "sec(".$scale.")=".(1/cos($scale))."<br>"; echo "csc(".$scale.")=".(1/sin($scale))."<br>"; } else { $scale=@($scale==0); echo "$php_errormsg"; } ?> </body> </html> 假設我倍數輸入0.666666666666666 結果如下: sin(2.09439510239)=0.866025403784 cos(2.09439510239)=-0.5 tan(2.09439510239)=-1.73205080757 cot(2.09439510239)=-0.57735026919 sec(2.09439510239)=-2 csc(2.09439510239)=1.15470053838 結果正確 可是我輸入0 結果是* 忘了寫倍數了 拜託各位看看哪裡有問題 感激不盡 -- ※ 發信站: 批踢踢實業坊(ptt.cc), 來自: 140.112.130.165 ※ 文章網址: https://www.ptt.cc/bbs/PHP/M.1463639210.A.1C1.html

05/19 14:29, , 1F
恭喜你踩到php的#1地雷: empty("0") === true
05/19 14:29, 1F

05/19 14:39, , 2F
學php第一件事就是記起來intval() floatval() strval()
05/19 14:39, 2F

05/19 18:07, , 3F
get post 有沒輸入用 == "" 檢查(陣列除外)
05/19 18:07, 3F

05/20 12:57, , 4F
isset($_POST["scale"])
05/20 12:57, 4F

05/21 09:05, , 5F
樓上 isset($_POST["scale"])要寫在哪裡呢?
05/21 09:05, 5F

05/21 10:58, , 6F
你code是抄來的嗎?怎麼會連要寫在那都不知道?
05/21 10:58, 6F

05/21 11:15, , 7F
不是 我參考人家寫的 然後再修改
05/21 11:15, 7F
程式碼如下(有isset()這個函數): <!doctype html> <html> <head> <style> .press { width:162px; } .error { color:#F00; } </style> <meta charset="utf-8"> <title>三角函數</title> </head> <body> <?php $scaleErr=""; settype($scale,"double"); //scale變成double型態 if ($_SERVER["REQUEST_METHOD"] == "POST") { if (empty($_POST["scale"])) { $scaleErr = "忘了寫倍數了"; } else { $scale=test_input($_POST["scale"]); if(isset($_POST["scale"])){ $scale=$scale*pi(); //倍數可以是小數或整數 } } } function test_input($data) { //if(!is_string($data)) $data='scale'; $data = trim($data); $data = stripslashes($data); $data = htmlspecialchars($data); return $data; } ?> <form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>"> 請輸入倍數:<input type="text" name="scale" class="press"> <span class="error">* <?php echo $scaleErr;?></span> <br><br><input type="submit" name="submit" value="送出"><br> </form> <?php if($scale!=0){ echo "<br>"; echo "sin(".$scale.")=".sin($scale)."<br>"; echo "cos(".$scale.")=".cos($scale)."<br>"; echo "tan(".$scale.")=".tan($scale)."<br>"; echo "cot(".$scale.")=".(1/tan($scale))."<br>"; echo "sec(".$scale.")=".(1/cos($scale))."<br>"; echo "csc(".$scale.")=".(1/sin($scale))."<br>"; } else { $scale=@($scale==0); $scale=floatval($scale); echo "$php_errormsg"; } ?> </body> </html> 輸入非0時結果對 可是輸入0還是一樣 *忘了寫倍數了 拜託各位看一下是哪裡有問題 感激不盡 ※ 編輯: todo70192 (59.125.122.241), 05/21/2016 11:39:01

05/21 13:22, , 8F
這麼多個答案你就沒個都試試吧,要改的是 empty($_POST
05/21 13:22, 8F

05/21 13:22, , 9F
那邊
05/21 13:22, 9F

05/21 14:09, , 10F
先去看入門書吧
05/21 14:09, 10F

05/22 04:47, , 11F
05/22 04:47, 11F

05/22 04:52, , 12F
看Return Values那段
05/22 04:52, 12F
文章代碼(AID): #1NFLog71 (PHP)