I'm trying to have the loop stop before it reaches the designated number of repeats if the value being calculated is equal to another variable. I have a break in an if statement but it doesn't seem to do anything as it just continues to loop until it reaches the designated end value.
echo "<h4>iteration Stages</h4>\n";
// looping the math for each iteration
for ($i=1; $i <= $iterations ; $i++) {
$estimate = 0.5 * ($estimate + $number / $estimate);
if ($estimate == $real){
echo round($estimate, 2);
break;
} else {
echo round($estimate, 2);
echo " -- \n";
}
}
Related
I have an array of values both positive and negative:
$numbers=['10','-2','-1','8','-7','1','-2','-3'];
I need to echo the results as:
numbers[0]=10;
numbers[1]=8;
numbers[2]=7;
numbers[3]=8;
numbers[4]=1;
numbers[5]=1;
numbers[6]=-1;
numbers[7]=-4;
Basically I take the first value that is always positive, echo that value, subtract the first negative value, echo the results, the second, etc until I found the next positive value, I echo that value, subtract from this value that becomes now reference the second negative value and so on...
I tries this in a loop but I can't manage to "break" the results after finding the second positive number - the numbers keep adding at the result from the first set of positive + negative values - even when using unset....
$i=0;
$sum=0;
while ($i < count($numbers)){
$sum=$sum+$numbers[i];
if($numbers[i]>0)
{
echo $numbers[i];
}
else
{
echo $sum;
}
}
You need to reset $sum to the number whenever you get a positive number.
foreach ($numbers as $i => $num) {
if ($num > 0) {
$sum = $num;
} else {
$sum += $num;
}
echo "numbers[$i] = $sum<br>";
}
$numbers=['10','-2','-1','8','-7','1','-2','-3'];
$i=0;
// there is no need initializing sum here since you it will be the first number
$sum=0;
while ($i < count($numbers)){
// $sum=$sum+$numbers[$i]; This is not needed
if ($numbers[$i] > 0) {
// if the $numbers[$i] is greater than 0 then it is a positive number
// you set $sum to the new positive number
$sum = $numbers[$i];
} else {
//else you perform arithmetic function here
// and since $numbers[$i] is a negetive number adding it will substract from $sum
$sum += $numbers[$i];
}
// You're concern about the sum so you should do your logic before echoing
echo $sum;
// Always remember to increment as while loop wont do that for you
$i++;
}
I need to find the averege after using a loop counting ever 3rd to a 100. The loop part is easy enough, but I need to sum every value then divide the sum on the total of values.
for ($x = 3; $x < 100; $x+=3) {
echo $x.", ";
}
This is the loop I need to use. How to I sum the values this produces and how do I find how many values this loop produces?
I believe the intention here is to learn about loops, otherwise this stuff can be done without looping too.
For learning purpose, you can simply introduce two variables count and sum and compute them inside the loop. For count, you just increment it on each iteration. For sum, you add the current value of x into sum. After the loop you print both variables.
$count = 0;
$sum = 0;
for ($x = 3; $x < 100; $x+=3) {
echo $x.", ";
$count++;
$sum+=$x;
}
echo $sum;
echo $count;
add your elements into an array and then use array_sum to sum the array elements , then divide the sum by the count of your array
$arr = [];
for ($x = 3; $x < 100; $x+=3) {
// echo $x.", \n";
$arr[] = $x;
}
print_r(array_sum($arr) / count($arr));
// Output : 51
$i=0;
$tempx=0;
for ($x = 3; $x < 100; $x+=3) {
//total sum
$tempx = $tempx + $x;
//count of how many times the loop ran in this case 33 times
$i++;
}
//first $i was 0 so we add 1
$i=$i + 1;
//getting the average
$average=$tempx / $i;
echo $average;
//output
For the last answer i think we should not do:
//first $i was 0 so we add 1 $i=$i + 1;
Regards
I'm writing a code to solve a problem.one of my functions is not working properly.
function check_factor($sqr,$num)
{
for($i = $sqr ; true ; $i++)
{
$n = pow($sqr,2) - $num;
$s = sqrt($n);
if(is_int($s))
{
return $i;
}
}
}
I know that $s is a "double" , but even when I limit my loop counter to 2,I'll get an endless loop.
What am I missing here? why the function doesnt simply return null? and why I get Infinite loop even when there are 2 iterations?
true is making it an infinite loop
you will always get an infinit loop because sqrt() returns float means
$s = sqrt($n);
$s is a float now
and your test is testing if $s is an integer so it will be an infinit loop even after $i=2 the loop will always stuck and the $i=2 in every loop but
if you change the code to this
<?php
function check_factor($sqr,$num)
{
echo "<br>";
for($i = 1 ; $i < 3 ; $i++)
{
echo " in the loop $i<br>";
$n = pow($sqr,2) - $num;
echo "$n<br>";
$s = sqrt($n);
echo "$s<br>";
if(is_int($s))
{
echo "in the if <br>";
return $i;
}
}
return 0;
}
$val=0;
$val = check_factor(5,2);
echo "<br>$val<br>";
?>
the out put should be like this
in the loop 1
23
4.7958315233127
in the loop 2
23
4.7958315233127
0
and that's it. i hope i helped.
According to the manual: PHP function sqrt() always returns a float and NEVER an integer.
Check http://php.net/manual/en/function.sqrt.php
How do you calculate (sum) + a value in foreach loop?
I am working on a cricket application where i have to count the loop for each 6 times and then count specific value and then echo the total.
I have a code not exact but something like this.
And there are two values:
Balls $balls['1']; array like 1,2,3,4,5 and up to 300-1000 balls
Runs $balls['6']; array like 2,3,1,5 random numbers could be any;
Values comes from mysql table columns balls and runs
foreach( $balls as $ball ){
$countball++;
// here is what i need to know how do i calculate the values of $ball + $ball?
// so i can echo it inside the below if condition?
$runs = $ball['runs'] + $ball['runs']; // not working
if($countball == 6){
echo $runs;
}
$runs+= $ball; // reset the ball counting to continue addition from loop?
// and reset the
}// end foreach
however something like this works fine for the first $countball == 6. but after that it does not show the exact value
You forget to reset the $countball.
You may change the if part as :
if($countball == 6)
{
echo $runs;
$countball = 0;
}
Maybe this is what you need:
$runs = 0;
foreach( $balls as $ball ){
$runs += $ball['runs'];
}
echo $runs;
With help of #Barmar from above i got the desired output as followings
$runs = 0;
$countball=0;
foreach( $balls as $ball ){
$countball++;
$runs += $ball['runs'];
if($countball == 6){
// reset runs from current loop runs for next, if i reset $runs = 0
// for some reason it does not (SUM) + this loops $ball['runs'] with last 5;
$runs = $ball['runs'];
$countball=0;
}// end if $countball == 6
}// end foreach
echo $runs;
I have a grid with 42 nrs where I will use the rand() function to pick out numbers from the grid and and mark them
so far I came up with
<?php
$row="";
print ("<table border=\"1\">");
for ($i=0; $i<6; $i++)
{
print ("<tr>");
for ($j=0; $j<7; $j++)
{
$random = rand(1,42);
$row += "(string)$random";
$som = $som + 1;
print("<th>".$som);
}
("</tr>");
}
print ("</table>");
print ("$rij");
// here I'm just testing to see if I can get a list of random numbers
for ($i=0; $i<6; $i++){
$randomNr = rand(1,42);
echo "$randomNr<br/>";
}
?>
I guess the idea is to match the numbers out of the rand function to the indexes of the table. But i'm really stuck here at getting the table to convert to an arra so I can match the index with the random numbers.
You're probably not too far off with your own attempt. You would just need to generate 6 random unique numbers and compare against them. Easiest way to do that is to generate an array using range() and pick the random numbers with array_rand() (which actually returns indexes, so you need a bit of additional code to get the values). Then you just need to find whether the currently outputted number is in the chosen number array using in_array()
Here's an example function of the general case that expands Sondre's example a bit. The function in the example takes following arguments: Total random numbers picked, Smallest number in the grid, Biggest number in the grid and the numbers per row in the grid. The function returns the generated HTML table source a string.
<?php
function generateHighlightedLotteryTable ($count = 6, $min = 1, $max = 42, $perRow = 7)
{
// Generate the picked numbers (actually we just get their indexes)
$nums = array_rand(range($min, $max), $count);
$output = "<table>\n";
for ($n = $min; $n <= $max; $n++)
{
// get "index" of the number, i.e. $min is the first number and thus 0
$i = $n - $min;
if ($i % $perRow == 0)
{
$output .= "<tr>";
}
// If the current number is picked
if (in_array($i, $nums))
{
$output .= "<td><strong>$n</strong></td>";
}
// If the current number hasn't been chosen
else
{
$output .= "<td>$n</td>";
}
if ($i % $perRow == $perRow - 1)
{
$output .= "</tr>\n";
}
}
// End row, if the numbers don't divide evenly among rows
if (($n - $min) % $perRow != 0)
{
$output .= "</tr>\n";
}
$output .= "</table>";
return $output;
}
echo generateHighlightedLotteryTable();
?>
I hope this is what you were trying to achieve.
This would create a grid of 42 numbers and mark out a random one. If you want to mark out more create and array and check against that insted of just the rand variable. In you're original code there you were actually running the rand-function 42 times which I guess is unintended.
EDIT: Or did you need the grid to be filled with random numbers?
$rand = rand(1, 42);
echo "<table>";
for($i = 1;$i <= 42; $i++) {
if($i%7 == 1) {
echo "<tr>";
}
$print = $rand == $i ? "<strong>" . $i . "</strong>" : $i;
echo "<td>" . $print . "</td>";
if($i%7 == 0) {
echo "</tr>";
}
}
echo "</table>";