[SOLVED] Function problem

[macattack]

I have created a simple function (the work can be done without a function, I'm just exploring how they work). I can't get the function to work for add and subtract, only for multiply and divide. The add and subtract answers only echo the answer, not the equation. Here is the code, with the form, which I assume works since most of the PHP code works.

 

Use this to magically do algebra!<br>
	<form action="learn.php" method="post">
		<label for="var1">Variable 1</label><input type="text" name="var1"><br>
		<label for="var2">Variable 2</label><input type="text" name="var2"><br>
		<select name="operator">
			<option>add</option>
			<option>subtract</option>
			<option>multiply</option>
			<option>divide</option>
		</select><br>
		<input type="submit" value="Perform selected operation"><br>
	</form>
<br>	
<?php
		$var1=$_POST["var1"];
		$var2=$_POST["var2"];
		$operator=$_POST["operator"	];

		function add($var1,$var2)	{
							echo $var1." + ".$var2." = ". $var1 + $var2 . "<br>";
						}
		function subtract($var1,$var2)	{
							echo $var1." - ".$var2." = ". $var1 - $var2 . "<br>";
							}
		function multiply($var1,$var2)	{
							echo $var1." x ".$var2." = ". $var1 * $var2 . "<br>";
							}
		function divide($var1,$var2)	{
							echo $var1." ÷ ".$var2." = ". $var1 / $var2 . "<br>";
							}
		if ($var1 >= 0)
		{	
			if ($var2 >= 0)
			{
				switch ($operator)
					{
						case "add":
							echo add($var1,$var2);
							break;
						case "subtract":
							echo subtract($var1,$var2);
							break;
						case "multiply":
							echo multiply($var1,$var2);
							break;
						case "divide":
							echo divide($var1,$var2);
							break;
					}
			}
			else
			{
				echo "Error.<br>";
			}
		}
		else
		{
			echo "Error.<br>";
		}	
	?>	

 

(edited by kenrbnsn to change the

tags to

)

[kenrbnsn]

You don't want to use "echo" in the function, you want to return the value computed:

<?php
function add ($v1, $v2) {
    return($v1 + $v2);
}

function subtract($v1, $v2) {
   return($v1 - $v2);
}

function multiply($v1, $v2) {
   return($v1 * $v2);
}

function divide($v1, $v2) {
   return($v1 / $v2);
}
?>

 

Ken