How to sum numbers with php using for loop?

Question

Can someone help me understand how to sum numbers?

For example, I want to use a for loop to sum all numbers from 1 to 10:

'1+2+3+4+5+6+7+8+9+10=?'

What have you tried so far? Where are you stuck? – Nico Haase May 23 '20 at 21:10 — Nico Haase, May 23 '20 at 21:10
https://stackoverflow.com/a/73924645/7186739 – Billu Oct 02 '22 at 09:14 — Billu, Oct 02 '22 at 09:14

score 6 · Accepted Answer · answered Nov 02 '14 at 12:40

6

Since you specifically said for loop:

<?php

$start = 1;
$end = 10;

$sum = 0;
for ($i = $start; $i <= $end; $i++) {
    $sum += $i;
}

echo "Sum from " . $start . " to " . $end . " = " . $sum;

answered Nov 02 '14 at 12:40

Ananth

4,227
2
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score 3 · Answer 2 · answered Nov 02 '14 at 12:41

3

Yes, it is pretty easy to do:

array_sum(range(1, 10))

or

$sequence = array(1,2,3,4,5,6,7,8,9,10);
array_sum($sequence);

answered Nov 02 '14 at 12:41

felipsmartins

13,269
4
48
56

Strictly speaking, this does not solve the question. The OP asked for a for loop – Nico Haase May 23 '20 at 21:13

score 3 · Answer 3 · answered Nov 02 '14 at 12:42

3

Not sure if I understand the question or not, but

$sum = 0;

for ($i = 1; $i <= 10; $i++) {
   $sum += $i;
}

echo 'The sum: ' . $sum;

Should sum the numbers between 1 and 10 into the $sum variable.

answered Nov 02 '14 at 12:42

Kakuriyo S

51
2

score 2 · Answer 4 · edited Nov 02 '14 at 12:44

2

this will do ... you have a lot of options to do this

$a=0;
for($i=0;$i==10;$i++)
{
    $a=$a+$i;
}
echo 'Sum= ' . $a ;

edited Nov 02 '14 at 12:44

Riad

3,822
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answered Nov 02 '14 at 12:42

Akhil Sidharth

746
1
6
16

...or `for ($i=1;$i==10;$i++)`, no need to add zero. – Gavin Simpson Nov 02 '14 at 12:52

score 2 · Answer 5 · edited Dec 08 '21 at 06:16

In fact, using a loop for this is the least efficient way. This is an arithmetic sequence and can be calculated using the formula:

S = n*(a1+an)/2

where a1 is first element, an is last element, n number of elements.

// for 1..10 it would be: 
$sum = 10*(1+10)/2; 

// for 1..2000 it would be:
$sum = 2000*(1+2000)/2; 

// u can use the same formula for other kinds of sequences for example:
// sum of even numbers from 2 until 10:
$sum = 5*(2+10)/2; // 5 elements, first is 2, last is 10

score 0 · Answer 6 · answered May 12 '17 at 05:43

Try like this:

<form method="post">
Start:<input type="text" name="a">
End: :<input type="text" name="b">
<input type="submit" >
</form>

<?php

$start = $_POST['a'];
$end = $_POST['b'];

$sum = 0;
for ($i = $start; $i <= $end; $i++) {
    $sum += $i;
}

echo "<h2>Sum from " . $start . " to " . $end . " = " . $sum;


?>

score 0 · Answer 7 · edited May 23 '20 at 17:49

0

<?php

    $array = array(1,2,3,4,5,6,7,8,9,10);  
    $count = count($array);

    $sum = 0;

    for($i=0;$i<$count;$i++){
      $sum  += $array[$i];
    }
    echo $sum ;
?>

edited May 23 '20 at 17:49

Zhorov

28,486
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answered May 23 '20 at 16:29

score -1 · Answer 8 · answered Jul 23 '19 at 10:41

-1

Make 1+2+3+4+5 = ? by recursion function

<?php
    $n=1;
    echo Recursion($n);
    function Recursion($n){
        if ($n <=5){
            if($n<5){
                echo "$n+";
            }
            else echo "$n=";
        return $n+Recursion($n+1);
        }
    }
    ?>

answered Jul 23 '19 at 10:41

raqibnur

59
1
7

Please add some explanation to your answer such that others can learn from it - why should recursion help in any way here? There is no, absolutely no benefit of using recursion here – Nico Haase May 23 '20 at 21:11

How to sum numbers with php using for loop?

8 Answers8