In order to enhance everyone's understanding of the code, we put together a story to prank a classmate Wang Sixong.
In both chapters 4.1 and 3.2.5 we introduced the if and if...else structures. And we explained it very clearly.
Let's now use the if...else structure to write a small thing to enhance everyone's understanding of logic.
We will write a calculator based on the previous knowledge points:
<form>
<input type="text" name="num1">
<select name="fh">
<option value="jia"> + </option>
<option value="jian"> - </option>
<option value="c"> x </option>
<option value="chu"> / </option>
<option value="qy"> % </option>
</select>
<input type="text" name="num2">
<input type="submit" value="运算" />
</form>
<?php
$num1 = $_GET['num1'];
$num2 = $_GET['num2'];
$fh = $_GET['fh'];
if(!is_numeric($num1) || !is_numeric($num2)){
echo '请输入数值类型';
}
if($fh == 'jia'){
echo $num1 . '+' . $num2 . '=' . ($num1+$num2);
}
if($fh=='jian'){
echo $num1 . '-' . $num2 . '=' . ($num1-$num2);
}
if($fh=='c'){
echo $num1 . 'x' . $num2 . '=' . ($num1*$num2);
}
if($fh=='chu'){
echo $num1 . '/' . $num2 . '=' . ($num1/$num2);
}
if($fh=='qy'){
echo $num1 . '%' . $num2 . '=' . ($num1%$num2);
}
?>Assignment:
Write a calculator for ordinary years and leap years. Write a form, pass the year through get, and determine whether the year passed in is a numeric type. And it is required that if it is a leap year, it will prompt that it is a leap year, and if it is an ordinary year, it will indicate that this year is an ordinary year.
Leap year rules for ordinary years: The year can be evenly divisible by 4, but not by 100. Or if it is divisible by 400, it is a leap year, otherwise it is an ordinary year
