PHP while 循環加 2

Question

目前我有一個看起來像這樣的代碼：

for ($i=0; $i<=($num_newlines - 1); $i++) 
{
$tweetcpitems->post('statuses/update', 
                    array('status' => wordFilter("The item $parts[$i]  has been released on Club Penguin. View it here:   http://clubpenguincheatsnow.com/tools/swfviewer/items.swf?id=$parts[$id]")));
sleep(90);
}

我想做的是使“i++”部分加二而不是加一，但我該怎么做呢？ 請幫忙！

Answer 1

for ($i=0; $i<=($num_newlines - 1); $i+=2) {

Answer 2

$i++ : increment by one

$i+=2 : increment by two

$i+=3 : increment by three

ETC..

Answer 3

對於那些希望增加一對數字（如 1-2 到 3-4）的人：

解決方案一：

//initial values
$n_left = 1;
$n_right = 2;

for ($i = 1; $i <= 5; $i++) {
    
    print "\n" . $n_left . "-" . $n_right;   
    
    $n_left =+ $n_left+2;
    $n_right =+ $n_right+2; 
}
//result: 1-2 3-4 5-6 7-8 9-10

解決方案二：

for ($y = 0; $y <= 9; $y+=2) {
    
    print "\n" . ($y+1) . "-" . ($y+2);  

}
//result: 1-2 3-4 5-6 7-8 9-10