Convert .5 into 1/2

Question

I want to convert any number which ends in .5 so that it displays as the number followed by ½, but I don't want 0.5 to display as 0½ so I did it like this:

$used = str_replace("0.5", "&frac12;", $used);
$used = str_replace(".5", "&frac12;", $used);

However I've now realised that this also converts 20.5 into 2½ instead of 20½.

I'm sure there's a better way of doing it but I don't know how.

Examples:

5 returns "5"
5.5 returns "5&frac12;"
0.5 returns "&frac12;"
10.5 returns "10&frac12;"

I don't believe this is a duplicate of an existing question because that code is to replace or return "1/2" rather than "½"

can you list some condition on which fraction should be done and and on what not to be done — M A SIDDIQUI, Apr 06 '17 at 11:47
Possible duplicate of [PHP convert decimal into fraction and back?](http://stackoverflow.com/questions/1954018/php-convert-decimal-into-fraction-and-back) — TIGER, Apr 06 '17 at 11:52
@AndyGroom Is it fine now or do i change it for further requirement? — Sahil Gulati, Apr 06 '17 at 12:10
Possible duplicate of [Converting float decimal to fraction](http://stackoverflow.com/questions/14330713/converting-float-decimal-to-fraction) — Jadeye, Apr 06 '17 at 13:22
@Jadeye: That's a very different question than the one asked here. — Nisse Engström, Apr 06 '17 at 18:05

score 0 · Answer 1 · answered Apr 06 '17 at 18:00

Based on the examples above and lacking any further requirements, you could write:

<?php

  $n = "13.5";
  /* ... */
  $r = $n;
  $r = preg_replace ('/^0\.5$/', '&frac12;', $r);
  $r = preg_replace ('/\.5$/', '&frac12;', $r);

  echo "$r\n";

You can combine the above into a single replacement:

  $r = preg_replace ('/(^0|)\.5$/', '&frac12;', $n);

Sahil Gulati · Accepted Answer · 2017-04-07T07:00:23.890

-1

PHP code demo(In HTML it will work fine)

<?php
$number="10.5000";
if(preg_match("/^[1-9][0-9]*\.5[0]{0,}$/", $number))
{
    echo $used = preg_replace("/\.5[0]{0,}$/", "&frac12;", $number);
}
elseif(preg_match("/^[0]*\.5[0]{0,}$/", $number))
{
    echo $used = str_replace("$number", "&frac12;", $number);
}
else
{
    echo $number;
}

Output: 10½

edited Apr 07 '17 at 07:00

answered Apr 06 '17 at 11:51

Sahil Gulati

15,028
4
24
42

1

This doesn't seem to work for me, is it because your sample entry ends in a zero (ie. like currency) whereas my numbers are unformatted. My values will be like 10.5 rather than 10.50 – Andy Groom Apr 06 '17 at 12:01
@AndyGroom It will work fine for that as well you can check. I have updated my post keeping all the requirements in mind, specified by you. – Sahil Gulati Apr 06 '17 at 12:03
*"I don't want 0.5 to display as 0½"*. What happens if `$number` is "0.5"? – JJJ Apr 06 '17 at 12:04
@JJJ then it just returns ½ – Andy Groom Apr 06 '17 at 12:08
@Sahilgulati my mistake sorry – Andy Groom Apr 06 '17 at 12:08
@AndyGroom This code does *not* return just "½". – JJJ Apr 06 '17 at 12:08
1

The body of the second branch can be simplified to: `echo "½";`. – Nisse Engström Apr 06 '17 at 17:25
@NisseEngström I have updated my post, can you please check again. If still there is any issue, can you let me know – Sahil Gulati Apr 07 '17 at 07:01
@JJJ I have updated my post, can you please check again. If still there is any issue, can you let me know – Sahil Gulati Apr 07 '17 at 07:01
1

I didn't downvote, but this is extremely convoluted for a simple task. `if($number=="0.5") { $number="½"; } else { $number=str_replace(".5", "½", $number);}` – JJJ Apr 07 '17 at 07:08
@JJJ What you are saying is correct but there can be a case when we have a number like this `10.5000` then it will return like this `10½000` which is invalid. that's why i have handled it this way. But i dont know why people are downvoting :( – Sahil Gulati Apr 07 '17 at 07:15
You don't know if there can be such a case. The OP didn't say anything like that, it's possible that it's guaranteed that there are no trailing zeroes. – JJJ Apr 07 '17 at 07:18
Even if there can be trailing zeroes this could be done with one line of regex. – JJJ Apr 07 '17 at 07:20
@JJJ Sorry to say sir, I am not arguing just take a case when number is `10.566` – Sahil Gulati Apr 07 '17 at 07:20

Convert .5 into 1/2

2 Answers2

Linked