regex replace single match from right of string

Question

I need to search and replace in a string, I want to replace the last occurrence of a string.

Here's my working code (which just does a normal search/replace):

PREG_REPLACE("/(\b{$abbr}\b)/i", "$long" , $street_address)

Example of expected results:

I want only the last occurrence of St replaced with Street.

anubhava · Accepted Answer · 2012-01-09 20:18:14Z

2

You can use negative lokahead like this:

$str = "123 St Martin St";
$abbr="(\b)St(\b)";
$long="Street";
var_dump(preg_replace("~$abbr(?!.*?$abbr)~", "$1" . $long . "$2", $str));

OUTPUT:

string(20) "123 St Martin Street"

answered Jan 9, 2012 at 20:18

anubhava

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1 Comment

This worked well and accommodated various variations of abbreviations. Thanks.

Joop Eggen · Accepted Answer · 2012-01-09 23:02:35Z

1

PREG_REPLACE("/(.*(\b{$abbr}\b.*)*)\b{$abbr}\b/i", "$1$long" , $street_address )

This might be relatively inefficient.

answered Jan 9, 2012 at 19:54

Joop Eggen

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This only works if the string has st in it and also ends with st.

Rocket is right -- it depends on the value being present elsewhere in the string.