[RESOLVED] limiting a string to a number of words?

[stevesweetland]

Okeydokey.

$string = "My name is stephen and i dont know how to do stuff or things.";


print $string;

your challenge, if you choose to accept it, is to get the above code to output

"My name is stephen and"

however, you may not use substr, as the conditions of this competition are that you may only limit by the number of words in the string (5 complete words).

i COULD split the string into an array using explode, and then use a for statement to achieve the effect i need, but thats not only messy, its (to coin an american term) pretty 'wack' too.

(in case you're wondering, i thought id make the usual 'i dont know how to do this' process a little more interesting)

[harmor]

Is this good enough 🙂

$string = "My name is stephen and i dont know how to do stuff or things.";

$output = array();
list($output[], $output[], $output[], $output[], $output[]) = split('[ .-]', $string);

print "$output[4] $output[3] $output[2] $output[1] $output[0]"; 

[HalfaBee]

hamor, can you do my homework as well?

[harmor]

haha sorry but I can't.

I have a little better approach

$string = "My name is stephen and i dont know how to do stuff or things.";

$output = array();
list($output[], $output[], $output[], $output[], $output[]) = split('[ .-]', $string);

$string = sort($output);
$string = implode(" ",$output);

print $string;

[stevesweetland]

oo nice, didnt know i could do that.... thanks 🙂

but actually i need to limit to 30 words, is there something a little neater i could do?

[HalfaBee]

You could do it like this.

<?
$string = "My name is stephen and i dont know how to do stuff or things.";
for( $i=0,$w=0;$i<strlen($string);$i++ ) {
    if( $string{$i} == ' ' AND  ++$w==5 ) break;
    $output .= $string{$i};
}

print $output;

?>

[cahva]

Yeah many ways to do it. Too boring at work here 🙂:

<?php
$string = "My name is stephen and i dont know how to do stuff or things.";
echo getwords($string,5);

function getwords($string,$numwords) {
	$tmp = explode(' ',$string);
	array_splice($tmp, $numwords);
	return(implode(' ',$tmp));
}
?>

[HalfaBee]

I think mine is the least resource intensive attempt 😉

[stevesweetland]

HalfaBee wrote:

I think mine is the least resource intensive attempt 😉

can you prove that? lol

thanks guys...

.... and im spent.

[HalfaBee]

Umm. no.
Logically, one loop over a string, for the smallest amount of data needed, would have to be the best solution.
Using explode etc goes over the whole string, so if it had 3000 words every word would have to be detected.

Hope that makes your homework complete 😃

[cahva]

Its easy to test which one is faster thought..

<?php
$string = "My name is stephen and i dont know how to do stuff or things.";

$time_s = microtime_float();
for ($i2=0; $i2<1000; $i2++) {
        $output = getwords($string,5);
}
$time_e = microtime_float();

echo $time_e - $time_s."\n";

$time_s = microtime_float();
for ($i2=0; $i2<1000; $i2++) {
        $output = '';
        for( $i=0,$w=0;$i<strlen($string);$i++ ) {
            if( $string{$i} == ' ' AND  ++$w==5 ) break;
            $output .= $string{$i};
        }
}
$time_e = microtime_float();

echo $time_e - $time_s."\n";

function getwords($string,$numwords) {
        $tmp = explode(' ',$string);
        array_splice($tmp, $numwords);
        return(implode(' ',$tmp));
}

function microtime_float()
{
   list($usec, $sec) = explode(" ", microtime());
   return ((float)$usec + (float)$sec);
}
?>

Actually my way is much faster 🙂 Heres the output from shell. Upper time is from my function and other is halfabee's

cahva@karhu:~$ php timetest.php                                                                                                                                                   

0.28144288063049
1.1363370418549
cahva@karhu:~$ php timetest.php 
0.28236603736877
1.1340301036835
cahva@karhu:~$ php timetest.php 
0.28396701812744
1.1284329891205
cahva@karhu:~$ php timetest.php 
0.28598999977112
1.2064080238342

Machine is 300Mhz P3 so its a little slow 😃

[Weedpacket]

You know, you can limit the number of pieces [man]explode[/man] breaks a string into...