如何使脚本运行到某一点？

I got this code and for some reason $i++ doesn't work.It shows everything in the database and i just want 10 elements to be shown

if($i <= 10){
            while($row = mysqli_fetch_assoc($result)){

            echo '<li>'.$row['title'].'</li>';
            $i++;   
    }
}

A quick fix, change:

if($i <= 10){
    while($row = mysqli_fetch_assoc($result)){
        echo '<li>'.$row['title'].'</li>';
        $i++;   
    }
}

...to:

while($i <= 10 && $row = mysqli_fetch_assoc($result)){
    echo '<li>'.$row['title'].'</li>';
    $i++;   
}

Explanation:

Once you're in the if conditional block, that if condition never gets evaluated again. Only the while condition gets evaluated with each loop, so move the $i <= 10 into the while condition. Use an AND && because you want both conditions to be true to continue looping.

But, ya, as Fred -ii- suggest, adding LIMIT 10 to your database query would reduce the amount of data you have to handle.

You should limit the result on your MySql query with LIMIT 10.
MySql LIMIT tutorial

i.e.:

select something from something LIMIT 10; 

Answering to your direct question:
Use break:

$i = 1;
while($row = mysqli_fetch_assoc($result)) {
    echo '<li>'.$row['title'].'</li>';
    $i++;
    if($i > 10) {
        break;
    }  
}

break ends execution of the current for, foreach, while, do-while or switch structure.