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tokio
05-08-2009, 10:17 PM
I want to find the summation of the integers from 1-100. So i want to find 1+2+3+4+5+...n. The first thing i thought about issuing a for loop to print the number of terms, and i was then thinking of a function to sum up all of the terms.

for (\$i=1; \$i<100;\$i++) {
print \$i; // prints terms 1-100
}

Any recommendations to find the summation of the terms? Thanks.

Tokio

Auax
05-08-2009, 10:40 PM
for (\$i=1; \$i<100;\$i++) {
\$sum = \$i;
}

echo \$sum;

I think that should do it.

Len Whistler
05-08-2009, 10:47 PM
This will output the results line by line. An echo outside the loop would be the final total.

<?php
\$array = range(1,100);

foreach (\$array as \$value) {
\$sum = \$sum + \$value;
echo "\$sum<br>";
}
?>

---------

XtremeGamer99
09-29-2009, 08:17 AM
Alternatively, you can use the arithmetic sequence equation:
(n/2)*(2a+(n-1)), where n = max number, a = min number.

<?php

\$a = 1;
\$n = 100;

\$sum = (\$n/2)*(2*(\$a)+(\$n-1));

echo sum; // echos '5050'

?>

EDIT: woah, didn't realize this topic was old. Was using the search function. <_<