三個數字的平均值

Question

我有一個Form.html和Form.php文件。我的Form.html文件有3個文本輸入框，要求用戶在每個文件中輸入一個數字。我想在用戶點擊提交後回顯平均數。這是我到目前爲止，雖然經過我點擊提交的平均數量爲「0」

// The Average of Numbers 
$number1 = ['number3']; 
$number2 = ['number3']; 
$number3 = ['number3']; 

// How Many Numbers are in Our Set 
$numbersInSet = 3; 

// Get the Sum of the Numbers 
$average = $sum/$numbersInSet; 

echo "The average of the three numbers you entered is<b> $average<p>"; 

Answer 1

<?php 
// The Average of Numbers 
$number1 = isset($_POST['number1']); 
$number2 = isset($_POST['number2']); 
$number3 = isset($_POST['number3']); 

// How Many Numbers are in Our Set 
$numbersInSet = 3; 

if(is_numeric($number1) &&is_numeric($number2)&&is_numeric($number3)){ 
$sum=$number1+$number2+$number3; 

// Get the Sum of the Numbers 
$average = $sum/$numbersInSet; 
echo "The average of the three numbers you entered is<b> $average<p>"; 
} 

?> 

<form method="post"> 
<input type="text" name="number1" /> 
<input type="text" name="number2" /> 
<input type="text" name="number3" /> 
<input type="submit"> 
</form>