PHP Prepend Leading Zero Before Single Digit Number, On-The-Fly

PHP prepend leading zero before single digit number, on-the-fly

You can use sprintf: http://php.net/manual/en/function.sprintf.php

<?php
$num = 4;
$num_padded = sprintf("%02d", $num);
echo $num_padded; // returns 04
?>

It will only add the zero if it's less than the required number of characters.

Edit: As pointed out by @FelipeAls:

When working with numbers, you should use %d (rather than %s), especially when there is the potential for negative numbers. If you're only using positive numbers, either option works fine.

For example:

sprintf("%04s", 10); returns 0010

sprintf("%04s", -10); returns 0-10

Where as:

sprintf("%04d", 10); returns 0010

sprintf("%04d", -10); returns -010

Prepend leading zero before positive or negative single digit number

echo sprintf('%+03d', $number);

Formatting a number with leading zeros in PHP

Use sprintf :

sprintf('%08d', 1234567);

Alternatively you can also use str_pad:

str_pad($value, 8, '0', STR_PAD_LEFT);

Adding both leading and trailing zeros before/after any number in PHP

Maybe this could be a solution; it satisfies all commented cases:

$num = 10.5;
$padded="0000".$num."0000";
if (($dotpos = strpos($padded, ".")) !== FALSE) {
    $result = substr($padded, $dotpos-2, 2).".".substr($padded, $dotpos+1, 2);
} else {
    $result = sprintf("%02s", $num);
}
echo $result;

Cases:

num = 4 -> output = 04

num = 4.5 -> output = 04.50

num = 10 -> output = 10

num = 10.5 -> output = 10.50

Adding leading 0 in php

If it is coming from a DB, this is the way to do it on a sql query:

lpad(yourfield, (select length(max(yourfield)) FROM yourtable),'0') yourfield

This is will get the max value in the table and place the leading zeros.

If it's hardcoded (PHP), use str_pad()

str_pad($yourvar, $numberofzeros, "0", STR_PAD_LEFT);

This is a small example of what I did on a online php compiler, and it works...

$string = "Tutorial 1 how to";

$number = explode(" ", $string); //Divides the string in a array
$number = $number[1]; //The number is in the position 1 in the array, so this will be number variable

$str = ""; //The final number
if($number<10) $str .= "0"; //If the number is below 10, it will add a leading zero
$str .= $number; //Then, add the number

$string = str_replace($number, $str, $string); //Then, replace the old number with the new one on the string

echo $string;

PHP - Add leading zeros to number but keep maximum length

Use str_pad function of PHP

$input = 1;
$number = str_pad($input, 7, "0", STR_PAD_LEFT);

Adding numbers with leading zeros

With str_pad:

For($i=1; $i<=44; $i++){
    Echo str_pad($i,5,"0",STR_PAD_LEFT) ."\n";
}

https://3v4l.org/Pe3M2

Str_pad(start number, length of string you want, what type of padding, where to place the padding [left/right])

How to pad single-digit numbers with a leading 0

<?php foreach (range(1, 12) as $month): ?>
  <option value="<?= sprintf("%02d", $month) ?>"><?= sprintf("%02d", $month) ?></option>
<?php endforeach?>

You'd probably want to save the value of sprintf to a variable to avoid calling it multiple times.

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