How to add 3 numbers by loop using these 3 loops [ for, do , do while loop] in php-CodePudding

I'm starting to learn php today and I cannot figure out how to sum all 3 numbers by these loops [for, do, do while] loop. I can't even get passed through for loop.

Here is my current code :

<?php

$sum =0;

@$a= $_GET['a'];
@$b= $_GET['b'];
@$c= $_GET['c'];

for($i = $a; $i<=$c; $i  )
{
    $sum = $a  ;
}

echo "Sum of $a , $b , $c is ".$sum;

?>

<body>

<form>

Enter first number <input type = "text" name="a"><br>

Enter second number <input type = "text" name="b"><br>

Enter third number <input type = "text" name="c"><br>

<input type = "submit" value="add">

</form>

</body>

CodePudding user response：

you can add them in an array and then add them in the loop.

<?php
$sum =0;

$a= $_GET['a'];
$b= $_GET['b'];
$c= $_GET['c'];

$arr = array($a,$b,$c);

for($i = 0; $i <= count($arr); $i  )
{
    $sum  = $arr[$i];
}

echo "Sum of $a , $b , $c is ".$sum;
?>

CodePudding user response：

The setup you have isn't ideal for a loop as you would be manually creating an array, then looping which is backwards.

You could instead change your inputs so that you receive them as an array:

<?php

$sum = 0;
$values = $_GET['to_sum'];

for ($i = 0;$i <= count($values);$i  ) {
    $sum  = $values[$i];
}

echo "Sum of " . join(", ", $values) . " is " . $sum;

?>

<body>

<form>

Enter first number <input type = "text" name="to_sum[]"><br>

Enter second number <input type = "text" name="to_sum[]"><br>

Enter third number <input type = "text" name="to_sum[]"><br>

<input type = "submit" value="add">

</form>

</body>

CodePudding user response：

You can go through the code given below using all the loops mentioned in your question. for your convenience I have suppressed all the errors using @ sign.

<?php
    # setting variable a$ as array if not found in the get request
    $_GET['a'] = isset($_GET['a']) && $_GET['a'] ? $_GET['a'] : [];
    
    $forSum = 0; #inital the sum will be 0
    #calculate sum for every element present in the array
    for($i=0; $i < count($_GET['a']); $i  ) {
        @$forSum  = $_GET['a'][$i];
    }

    #print sum
    echo 'For loop sum : ' . $forSum;

    $whileSum = 0;
    $iterator = 0;
    #calculate sum for every element present in the array
    while($iterator < 3) {
        @$whileSum  = $_GET['a'][$iterator];
        $iterator  =1;
    }

    #print sum
    echo '<br / >While loop sum : ' . $whileSum;

    $doWhileSum = 0;
    $iterator = 0;
    #calculate sum for every element present in the array
    do {
        @$doWhileSum  = $_GET['a'][$iterator];
        $iterator  =1;
    } while($iterator < 3);

    #print sum
    echo '<br / >Do While loop sum : ' . $doWhileSum;
    echo '<br /><br />';

?>

<html>
<head>
    <title> Add With Loops </title>
</head>
<body>
    <form>
        First number <input type="text" name="a[]" value="<?php echo @$_GET['a'][0]; ?>"><br>
        Second number <input type="text" name="a[]" value="<?php echo @$_GET['a'][1]; ?>"><br>
        Third number <input type="text" name="a[]" value="<?php echo @$_GET['a'][2]; ?>"><br>
        <input type="submit" value="Add">
</form>
</body>
</html>