Question 41988 in PHP Question posted in
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PHP exercise loops

Using while loop to print 10-20 odd numbers on the screen, with <-> (exapmle 11-13-15-17-19, <-> not after 19).How to take the last number so as not to put a -. Thank you.

<?php

$x = 10;
while($x < 20){
   $x++;
   if($x % 2){
      echo $x. "-";
   }
}
Tags:

4

Answers


  1. 0

    You can push the odd values to an array and after the loop you can convert the array to a string with the implode (https://www.php.net/manual/en/function.implode.php) function.

    $x = 10;
$arr = [];
while($x<20){
  $x++;
  if ($x%2){
    $arr[] = $x;
  }
}
echo implode(",", $arr);
// output will be a comma seperated string

    without (helper)array
    You can use rtrim() (https://www.php.net/manual/de/function.rtrim.php) funktion.

    $str = "1,2,3,";
echo rtrim($str,",");
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  2. 0

    As mentioned in the comments, have a boolean variable say firstTime. If this is true, don’t prepend a hyphen, else if it is false, prepend it with a hyphen.

    <?php

$x = 10;
$firstTime = true;
while($x < 20){
   $x++;
   if($x % 2){
      echo ($firstTime ? "" : "-") . $x;
      $firstTime = false;
   }
}
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  3. 0

    Simple approach

    Imagine you are printing a list of numbers from 10 to 20. If it’s an even number, print the "-" symbol and if it’s odd number, print the number.

    <?php
$start = 10;
$end = 20;
while($start<$end)
{
  $n=$start;
  if($n>10)
  echo ($n%2==0)?"-":$n; //the gist is here
  $start++;
}
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