<title>php Implement Simple Calculator </title>
<meta http-equiv= "Content-type" content= "text/html;charset=gb2312" >
<?php
One-Way Branch
if (Isset ($_get["sub"))
{
$num 1=true;//Number 1 is an empty tag
$num 2=true;//number 2 is an empty tag
$numa =true;//Number 1 is a number
$numb =true;//Number 2 digits
$message = "";
Determine if the number 1 is empty
if ($_get["NUM1"]== "")
{
$num 1=false;
$message. = "The first number cannot be empty";
}
Judge whether the number 1 is a number
if (!is_numeric ($_get["NUM1"]))
{
$numa =false;
$message. = "First number is not a number";
}
Judge whether the number 2 is a number
if (!is_numeric ($_get["num2"]))
{
$numa =false;
$message. = "Second number is not a number";
}
Determine if the number 2 is empty
if ($_get["num2"]== "")
{
$num 2=false;
$message. = "Second number cannot be null";
}
if ($num 1 && $num 2 && $numa && $numb)
{
$sum = 0;
Multi-Channel Branch
Switch ($_get["YSF"]) {
Case "+":
$sum =$_get["NUM1"]+$_get["num2"];
Break
Case "-":
$sum =$_get["NUM1"]-$_get["num2"];
Break
Case "X":
$sum =$_get["NUM1"]*$_get["num2"];
Break
Case "/":
$sum =$_get["NUM1"]/$_get["num2"];
Break
Case "%":
$sum =$_get["NUM1"]%$_get["num2"];
Break
}
}
}
?>
<body>
<table align= "Center" border= "1" width= ">"
<caption><form action= "jisuanqi.php" >
<tr>
<td>
<input type= "Text" size= "5" name= "NUM1" "value=" <?php echo $_get["NUM1"];?> ">
</td>
<td>
<select name= "YSF" >
<option value= "+" <?php if ($_get["YSF"]== "+") echo "selected";?>>+</option>
<option value= "-" <?php if ($_get["YSF"]== "-") echo "selected";?>>-</option>
<option value= "x" <?php if ($_get["YSF"]== "x") echo "selected";?>>x</option>
<option value= "/" <?php echo $_get[ysf "]=="/"?" Selected ":";?>>/</option>
<option value= "%" <?php if ($_get["YSF"]== "%") echo "selected";?>>%</option>
</select>
</td>
<td>
<input type= "Text" size= "5" name= "num2" "value=" <?php echo $_get["num2"];?> ">
</td>
<td>
<input type= "Submit" value= "Calculate" name= "sub" >
</td>
</tr>
<?php
if (Isset ($_get["sub"))
{
Echo ' <tr><td colspan= 4 ' > ';
if ($num 1 && $num 2 && $numa && $numb)
{
echo "The result is:". $_get["NUM1"]. " ". $_get[" YSF "]." ". $_get[" num2 "]." = ". $sum;
}
Else
{
Echo $message;
}
Echo ' </td></tr> ';
}
?>
</form>
</table>
</body>
