size of array in perl script loop -

i using below commands find size of array

$size_x = @x; 

or

$size_x = $#x+1 ; 

both work when use in simple statement. when use them in loop, size becomes 1 number bigger. why happening in way. below example:

for ($i=1;$i<=10;$i++){  if (1**2+2**2>=1){ @x[$i] =2+3; $size_x = @x; } print "my size $size_x\n"; } 

here results:

my size 2 size 3 size 4 size 5 size 6 size 7 size 8 size 9 size 10 size 11 

the answer should 1 10 instead of 2 11, think. better way size correctly? thanks.

just side note: array elements in perl denoted starting $, not @. @x whole array, while $x[$i] $i'th element of array @x.

use warnings; should warn this.

(i know more comment answer, newbie i'm not yet allowed comment. sorry.)