goto等同于PHP版本<5.3.0？

Question

I need to use the goto operator in my code as I can't seem to think of a way around it. However the problem is my host only has PHP version 5.2.17 installed.

Any ideas?

Below is my code:

if ($ready !=="y")
{
    $check=mysql_query("SELECT `inserted` FROM `team`");
    $numrows  = mysql_num_rows($check);  

    $i="0";

    while ($i<$numrows && $row = mysql_fetch_assoc($check))
    {

        $array[$i] = $row['inserted'];
        $i++;

    }
    if (in_array("n", $array)) 
    {

        goto skip;

    }
    else
    {
        mysql_query("

            UPDATE game SET ready='y'

        ");
    }

}

skip:

Answer 1

There are a few anti-patterns in your code. Let's clean it up. I'll explain what's been changed in a jiffy.

if($ready !== "y") {
    $sth = mysql_query("SELECT inserted FROM team WHERE inserted = 'n'");
    if(mysql_num_rows($sth) > 0) {
        mysql_query("UPDATE game SET ready = 'y'");
    }
}

First things first: There is no need to perform a query, fetch all of the results, then loop through those results ( in_array ) looking for a specific value. Let the database do that for you by expressly looking only for rows where inserted is the string literal "n" .

Because we know that we're only getting "n" records back, we just need to check if there are any results. If so, run the query. If there are no "n" records, the UPDATE isn't run.

If you need to know that the UPDATE ran, add a check for it:

$ran_update = false;
if($ready !== "y") {
    $sth = mysql_query("SELECT inserted FROM team WHERE inserted = 'n'");
    if(mysql_num_rows($sth) > 0) {
        mysql_query("UPDATE game SET ready = 'y'");
        $ran_update = true;
    }
}
if($ran_update) {
// ...
}

Answer 2

You want to use the correct control word to break from the loop:

if ($ready !=="y")
{
    $check=mysql_query("SELECT `inserted` FROM `team`");
    $numrows  = mysql_num_rows($check);  

    $i="0";


    while ($i<$numrows && $row = mysql_fetch_assoc($check))
    {


    $array[$i] = $row['inserted'];
    $i++;

    }
    if (in_array("n", $array)) 
    {

        break;

    }
    else
    {
    mysql_query("

    UPDATE game SET ready='y'

    ");
    }

}

The break keyword will do exactly what you want: End the execution of the while loop. Never ever ever use a goto!

Answer 3

As a direct response to the title of this post:

do{

  if (!$condition){
    break;
  }

  // Code called if conditions above are met

}while(0);

//Code always called

In some circumstances, this, or a goto, can make for very tidy and readable code.

Answer 4

First, you could use a break to exit your initial loop. Second, if you need to test for anything, set a variable (must be global not local) as a flag or indicator before calling break , then do a conditional test statement where your skip line is to perform any additional steps you need.