PHP实现计算器小功能

本文实例为大家分享了PHP实现计算器小功能的具体代码，供大家参考，具体内容如下

<?phpif (isset($_POST[\'sub\'])) {$f = true;$error = \"有以上问题: <br>\";if ($_POST[\"num1\"] == \"\") {$f = false;$error .= \"第一个数不能为空.<br>\";} else {if(!is_numeric($_POST[num1])) {$f = false;$error .= \"第一个数字不是数字.<br>\";}}if ($_POST[\'num2\'] == \"\") {$f = false;$error .= \"第二个数字不能为空.<br>\";} else {if (!is_numeric($_POST[\'num2\'])) {$f = false;$error .= \"第二个数字不是数字<br>\";}}if ($f) {switch ($_POST[\'ysf\']) {case \'+\': $sum = $_POST[\'num1\']+$_POST[\'num2\'];break;case \'-\': $sum = $_POST[\'num1\']-$_POST[\'num2\'];break;case \'*\': $sum = $_POST[\'num1\']*$_POST[\'num2\'];break;case \'/\': $sum = $_POST[\'num1\']/$_POST[\'num2\'];break;case \'%\': $sum = $_POST[\'num1\']%$_POST[\'num2\'];break;}}}?>

<!doctype html><html><head><meta charset=\"utf-8\"><title>简易计算器</title><style>* {margin: 0px;padding: 0px;}#contains {width: 400px;margin: 50px auto;}h1 {width: 400px;text-align: center;color: #0F0;}table {margin-top: 20px;width: 400px;}input {background: yellow;border-radius: 20px;}input:hover {background: green;}select {background: yellow;border-radius: 20px;}td {background: #3F0;text-align: center;height: 30px;}#sub {border-radius: 25px;width: 50px;}</style></head><body><div id=\"contains\"><h1>简易计算器</h1><form action=\"Calculator.php\" method=\"post\"><table border=\"0\"><tr><td><input type=\"text\" name=\"num1\" value=\"<?php echo $_POST[\'num1\'];?>\" size=\"3\"/></td><td><select name=\"ysf\"><option <?php if($_POST[\'ysf\'] == \"+\") echo \"selected\";?> value=\"+\">+</option><option <?php if($_POST[\'ysf\'] == \"-\") echo \"selected\";?> value=\"-\">-</option><option <?php if($_POST[\'ysf\'] == \"*\") echo \"selected\";?> value=\"*\">*</option><option <?php if($_POST[\'ysf\'] == \"/\") echo \"selected\";?> value=\"/\">/</option><option <?php if($_POST[\'ysf\'] == \"%\") echo \"selected\";?> value=\"%\">%</option></select></td><td><input type=\"text\" name=\"num2\" value=\"<?php echo $_POST[\'num2\'];?>\" size=\"3\"/></td><td><input type=\"submit\" id = \'sub\' name=\"sub\" value=\"计算\"/></td></tr><tr><td colspan=\"4\"><?phpif ($f) {echo \"计算结果: <b>{$_POST[\'num1\']}{$_POST[\'ysf\']}{$_POST[\'num2\']} = {$sum}</b>\";} else {echo \"<b>$error</b>\";}?></td></tr></table></form></div></body></html>