APD1993 Posted January 24, 2012 Share Posted January 24, 2012 I have a flow control statement that has to write "1+2+3+4...+100" and then display the total (5050) on the webpage. The current code that I have is <html> <head><title>Adding Numbers Script</title></head> <body> <?php $num=0; $sum=0; while ($num<=99) { {$sum=$sum+$num++; echo "$num+ ";} } if ($num>99){$sum=$sum+$num; echo"$num= ";} echo "$sum"; ?> </body> </html> However, I was told that it could be made more efficient by only having one flow control statement in there, rather than the two I have at the moment (the while and the if statements). Can anyone help me make this more efficient? Thanks in advance, Andrew Quote Link to comment Share on other sites More sharing options...
Psycho Posted January 24, 2012 Share Posted January 24, 2012 The if() statement is unnecessary. The while() loop will ensure that $num will be >99 before it gets past the while. But, I don't think that loop is even necessary. Let me see if there is a math function to do that addition automatically. Quote Link to comment Share on other sites More sharing options...
Psycho Posted January 24, 2012 Share Posted January 24, 2012 To get the final sum this is all you need $first = 1; $last = 100; $sum = (($last - $first + 1) * ($first + $last)) /2; echo "Sum: {$sum}"; This adds all the consecutive numbers between the start number to the last number, i.e. 1 + 2 + 3 + . . . + 98 + 99 + 100 = 5050 Quote Link to comment Share on other sites More sharing options...
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