How to increment complete string in php?

Question

How to increase a complete string in php. Like abc should be converted to bcd. I tried

$i="abc";
$i++;
echo $i; //abd

But it increases only the last character.

I searched many question like this but I did not find any solutions.

Answer 1

You probably have read How to increment letters like numbers in PHP?.

However, the $i++ only works on a single char.

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So to get the desired output, we could simply:

1. Convert the string into an array using str_split()
2. Loop over them using a foreach() , change, or in my case create a new output
   1. 'Increase' the char using ++

<?php

$test = 'abc';
$output = '';

foreach (str_split($test) as $char) {
    $output .= ++$char;
}

echo $output;

The above code will produce:

bcd

as you can try in this online demo.

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A more compact solution would involve

• array_map as a loop
• A short function notation
• implode() to stitch back the array to a string

<?php

$test = 'abc';
$result = implode(array_map(fn ($c) => ++$c, str_split($test)));

echo $result;

Try it online!

Answer 2

We can do this by the following 3 steps:

1. Convert each character to an unsigned integer, by using php's built-in function ord().
2. Increment this integer by one (or by other number).
3. Convert it back to character (using php's built-in functon chr()).

$test = 'abc';
$output = '';

foreach (str_split($test) as $char) {
    $output .= chr(ord($char)+1);
}

echo $output;

See demo