Problem echoing a variable in OOP

<?php

class Tree{

private $_Type;
private $_Height = 1;

public function setType($_TheType){
$_Type = $_TheType;
echo '<b>'.$_Type.' tree has been cultivated.</b><br/>';
echo 'The height of '.$_Type.' Tree is '.$this->_Height.' meters<br/>';
}

public function oneYearPasses(){
$this->_Height++;
echo 'The'.$this->_Type.' grows to '.$this->_Height.' meter <br/>';
}

}

$OrangeTree = new Tree;
$OrangeTree->setType('Orange');
$OrangeTree->oneYearPasses();

$AppleTree = new Tree;
$AppleTree->setType('Apple');
$AppleTree->oneYearPasses();

$MangoTree = new Tree;
$MangoTree->setType('Mango');
$MangoTree->oneYearPasses();
?>

Why doesn't oneYearPasses method echo's the $_TYPE in the echo? echo 'The'.$_Type.' grows to '.$this->_Height.' meter <br/>';

$_Type = $_TheType;
should be
$this->_Type = $_TheType;

A better way to do this:


<?php

class Tree{

private $_Type;
private $_Height = 1;

public function setType($_TheType){
$_Type = $_TheType;
$return_val = '<b>'.$_Type.' tree has been cultivated.</b><br/>';
$return_val .= 'The height of '.$_Type.' Tree is '.$this->_Height.' meters<br/>';

return $return_val;
}

public function oneYearPasses(){
$this->_Height++;
$return_val = 'The'.$this->_Type.' grows to '.$this->_Height.' meter <br/>';

return $return_val;
}

}

$OrangeTree = new Tree;
echo $OrangeTree->setType('Orange');
echo $OrangeTree->oneYearPasses();

returning rather than echoing is often a better idea, but losing the constructor in place of a setter doesn't really make sense in this case, it allows you to change the type of the tree as many times as you like!