How to pick out a single digit in a number and replace it

So, I want to be able to get a digit, say all the number 5s from 423412534152345124 and change them to 7s or any other number. How do I do this?

I know I can add 2 to the 5s but I don't know how to select just the 5s.

Thanks

 

something like this:

<?php
$a = "423412534152345124";
$b = strtr($a, array("5"=>"7"));
echo "$b";
?>

Code (markup):

 

This sort of works. However I get '0.' and then 'E+64'. I just want this to change the numbers, so 5678 to something like, 5794.

Thanks

 

Weird, works fine for me, it outputs:

423412734172347124

Code (markup):

when I run it.

 

But say the number 1000111010100000111101010000111001110001010111110000101011110001. It doesn't work.

 

If i run this:

<?php
$a = "1000111010100000111101010000111001110001010111110000101011110001";
$b = strtr($a, array("1"=>"7"));
echo "$b";
?>

Code (markup):

it outputs:

7000777070700000777707070000777007770007070777770000707077770007 

Code (markup):

so works fine for me

 

try replacing the 1s with 0s and the 0s with 1s.

 

Ok, if i do this:

<?php
$a = "1000111010100000111101010000111001110001010111110000101011110001";
$b = strtr($a, array("1"=>"0","0"=>"1"));
echo "$b";
?>

Code (markup):

It outputs:

0111000101011111000010101111000110001110101000001111010100001110 

Code (markup):

so like I said, it does work.

 

@Ipodman79 are you using 32 bit PHP?

 

O

i don't know, how do I check?

 

I'm wondering if you are treating an integer as a string, whereas @malky66 is not.

Try Konrad's answer on:


http://stackoverflow.com/questions/...ared-hosting-is-running-32-or-64-bit-with-php

 

I used that

I used Konrad's solution and it looks like I'm using 64-bit php. However I need this to be able to run on 64 bit and 32 bit.

Does that help?

 

You still haven't answered @ryan_uk's question. Do you treat your numbers as strings?

As you can see, @malky66 uses quotes around his variables.

 

I have

$number = 11010100101001101010101;

PHP:

Is that treating it as a string?

 

Try to use the var_dump() function:

var_dump( $number );

PHP:

You'll see, it's an integer Now you can use single quotes and check again; it'll be a string.

 

No, you can convert in different ways, e.g.:

$string = "$number";
$string = (string) $number;
$string = strval($number);

PHP:

Research it as there are pros and cons to some methods and also additional ones such as sprintf, settype, etc.

Or even handle it as a string from the start.