3 Ways To Add Commas To A Number In PHP

Welcome to a short tutorial on how to add commas to numbers in PHP. Need to format and present a “nice-looking” number to the users?

That covers the quick basics, but read on if you need more concrete examples.

 

 

TABLE OF CONTENTS

 

 

EXAMPLE CODE DOWNLOAD

Source code on GitHub Gist

Just click on “download zip” or do a git clone. I have released it under the MIT license, so feel free to build on top of it or use it in your own project.

 

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METHOD 1) NUMBER FORMAT

<?php
// (A) THE NUMBER
$num = 12345.675;
 
// (B) ADD COMMAS
$formatted = number_format($num, 2);
echo $formatted; // 12,345.68
 
// (C) BLANK SPACES AS THOUSANDS SEPARATOR
$formatted = number_format($num, 3, ".", " ");
echo $formatted; // 12 345.675
 
// (D) ROUND BEFORE FORMATTING
$formatted = round($num, 2, PHP_ROUND_HALF_DOWN);
$formatted = number_format($formatted, 2);
echo $formatted; // 12,345.67

The number_format() format function is probably the easiest way to add commas to a number, and it takes in 4 parameters:

• The first parameter is the number itself.
• Followed by the number of decimal places.
• The decimal separator defaults to . if omitted.
• Lastly, the thousands separator defaults to , if omitted.

This shouldn’t be much of a mystery, but take extra note that the rounding cannot be controlled. If you have your own “special rounding rules”, you will have to do it manually before calling number_format().

 

 

METHOD 2) REGULAR EXPRESSION

<?php
// (A) THE NUMBER
$num = 12345.78;
 
// (B) INSERT COMMAS
$pattern = "/\B(?=(\d{3})+(?!\d))/";
$replace = ",";
$commas = preg_replace($pattern, $replace, $num);
echo $commas; // 12,345.78

The good old regular expressions… Not going to explain too much on this one, as it is a whole can of worms. But in this example, that $pattern simply inserts a comma for every 3 digits.

 

METHOD 3) MANUAL FORMAT

<?php
// (A) THE NUMBER
$num = 12345.678;
//$num = 1234567;
 
// (B) SPLIT WHOLE NUMBER & DECIMAL PLACES
$arrange = explode(".", $num);
 
// (C) ADD COMMAS
$arrange[0] = strrev($arrange[0]);
$arrange[0] = str_split($arrange[0], 3);
$arrange[0] = implode(",", $arrange[0]);
$arrange[0] = strrev($arrange[0]);
 
// (D) DEAL WITH DECIMALS - ROUND UP OR ROUND DOWN AS REQUIRED
if (isset($arrange[1])) {
  $arrange[1] = "0.$arrange[1]";
  $arrange[1] = (string)round($arrange[1], 2);
  $arrange[1] = substr($arrange[1], 2);
}
 
// (E) COMBINE BACK
$num = isset($arrange[1])
  ? "$arrange[0].$arrange[1]"
  : $arrange[0] ;
echo $num;

While number_format() is convenient, we cannot control the rounding and number of digits to add a separator. So if you want “absolute control”, a manual process is the only way to go. This is a little confusing at first, but let us go through this quickly:

• First, we don’t want to add commas to the decimals. So we split the whole number and decimals apart – $arrange = explode(".", $num)
• Next, we reverse the whole number. For example, 1234 to 4321 – $arrange[0] = strrev($arrange[0])
• Then, add commas to the number (split into 3 digits then implode). For example, 4321 to 432,1 – $arrange[0] = implode(",", str_split($arrange[0], 3))
• Reverse the number to get back the “original”. For example 432,1 to 1,234 – $arrange[0] = strrev($arrange[0])
• Lastly, combine the whole numbers and decimals back – $num = "$arrange[0].$arrange[1]".

Long-winded, but this offers a lot of control – Round the number however you wish, set the number digits to add a comma, specify the separator, etc…

 

 

 

LINKS & REFERENCES

• Number Format – PHP
• PHP Regular Expression Insert Comma – Stack Overflow