Copy codeThe Code is as follows: <Head>
<Title> PHP implements a simple calculator </title>
<Meta http-equiv = "Content-Type" content = "text/html; charset = gb2312">
</Head>
<? Php
// Single branch
If (isset ($ _ GET ["sub"])
{
$ Num1 = true; // whether the number 1 is null
$ Num2 = true; // whether the number 2 is null
$ Numa = true; // whether number 1 is a number
$ Numb = true; // whether the number 2 is a digit
$ Message = "";
// Judge whether the number 1 is null
If ($ _ GET ["num1"] = "")
{
$ Num1 = false;
$ Message. = "the first number cannot be blank ";
}
// Determine whether number 1 is a number
If (! Is_numeric ($ _ GET ["num1"])
{
$ Numa = false;
$ Message. = "the first number is not a number ";
}
// Determine whether number 2 is a number
If (! Is_numeric ($ _ GET ["num2"])
{
$ Numa = false;
$ Message. = "the second number is not a number ";
}
// Judge whether number 2 is null
If ($ _ GET ["num2"] = "")
{
$ Num2 = false;
$ Message. = "the second number cannot be blank ";
}
If ($ num1 & $ num2 & $ numa & $ numb)
{
$ Sum = 0;
// Multiple branches
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 = "500">
<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 = "computing" name = "sub">
</Td>
</Tr>
<? Php
If (isset ($ _ GET ["sub"])
{
Echo '<tr> <td colspan = "4"> ';
If ($ num1 & $ num2 & $ numa & $ numb)
{
Echo "Result :". $ _ GET ["num1"]. "". $ _ GET ["ysf"]. "". $ _ GET ["num2"]. "= ". $ sum;
}
Else
{
Echo $ message;
}
Echo '</td> </tr> ';
}
?>
</Form>
</Table>
</Body>
</Html>
