Adding leading 0 in php

Question

I have - tutorial 1 how to make this - tutorial 21 how to make this - tutorial 2 how to make this - tutorial 3 how to make this and i need - tutorial 01 how to make this - tutorial 21 how to make this - tutorial 02 how to make this - tutorial 03 how to make this so i can order them properly. (adding leading 0 when single digit is found) What would be a php method to convert? thanks in advance note-please make sure that it identifies the single digit numbers only first and then add the leading zero

Accepted Answer

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;
```

Adding leading 0 in php

Solution

Problem